UAH Temperature Update for April, 2011: +0.12 deg. C

May 10th, 2011 by Roy W. Spencer, Ph. D.


2010 01 0.542 0.675 0.410 0.635
2010 02 0.510 0.553 0.466 0.759
2010 03 0.554 0.665 0.443 0.721
2010 04 0.400 0.606 0.193 0.633
2010 05 0.454 0.642 0.265 0.706
2010 06 0.385 0.482 0.287 0.485
2010 07 0.419 0.558 0.280 0.370
2010 08 0.441 0.579 0.304 0.321
2010 09 0.477 0.410 0.545 0.237
2010 10 0.306 0.257 0.356 0.106
2010 11 0.273 0.372 0.173 -0.117
2010 12 0.181 0.217 0.145 -0.222
2011 01 -0.010 -0.055 0.036 -0.372
2011 02 -0.020 -0.042 0.002 -0.348
2011 03 -0.101 -0.073 -0.128 -0.342
2011 04 0.120 0.199 0.042 -0.229

NEW! Monthly UAH temperature reports and global images.

La Nina Fades
The global average lower tropospheric temperature anomaly for April 2011 jumped up to +0.12 deg. C, further evidence that La Nina is fading.

I have also updated the global sea surface temperature anomaly from AMSR-E through yesterday, May 9 (note that the base period is different, so the zero line is different than for the lower tropospheric temperature plot above): Gifts, gadgets, weather stations, software and here!

37 Responses to “UAH Temperature Update for April, 2011: +0.12 deg. C”

Toggle Trackbacks

  1. bill hunter says:

    Could you explain why the global temperature is above the zero anomaly line on your monthly report but on the Discover site April was well below the average line.

    When I look at the Discover site home page it says data is included since 1979 and if I check all the yearly check boxes for the channel 05 graph the average is clearly not an average of those years as the average sits much lower. In fact, at some points, particularly in the fall, the average line is virtually the lowest value on the chart.

  2. CatrunJ says:

    The new temperature anomaly is somewhat interesting. But what I think we are all wondering is how the sudden increase in global temperature is related to solar and volcanic activity, the AO, AMO, PDO, and ENSO. If only somebody out there could come up with a theory to explain it all! That would be truly interesting!

  3. Ray says:

    bill hunter,
    The April anomaly was somewhat higher than I would have expected from the April AQUA CH5 anomaly from the discover site, which was about 0.1c below “normal” when the data ended on April 25th.
    Normally, that would “normally” be equivalent to a UAH anomaly of about 0.4c. Of course, there is a margin of error, and it is possible that AQUA CH5 temperatures were higher during the last few days of the month.
    I think the average on the CH5 graph may cover years prior to the ones shown on the graph, which were, of course, much lower. Logically it should cover the period 1981-2010, which is the base period for UAH.

  4. Ray says:

    Sorry, too many “normally’s”.

  5. An Inquirer says:

    Bill Hunter,
    Each month, Dr. Spencer reports a monthly anomaly which is inconsistent with the daily #s and average from the Discover webpage. Each month, we ask Dr. Spencer for an explanation, and each month we are left with the need to speculate. Perhaps the average is based on the old 20 year average instead of the 30 year average that Dr. Spencer now uses. Perhaps the average is based on #s that need to be adjusted for orbital drift and decay. Perhaps . . .?
    In the recent past, the daily #s needed to be adjusted for orbital drift and decay, but now Dr. Spencer uses AQUA #s for Channel 5 which need not be adjusted for orbital drift and decay.
    You will soon see a post from Ray who tries to forecast the monthly # that Dr. Spencer will post based upon a formula which is a function of daily #s and the reported average.

  6. The global temperatures are responding exactly the way I thought they would. So far so good. The trend is lower ,and the trend will not be straight down, but, will exhibit many counter trends, within the main downward trend.

    As I have said ,this decade will be the decade of global cooling. Solar activity should remain low,with an increase in geological activity,while PDO remains in cold phase with AMO to follow. La Ninas’s will rule this decade.


    I am as confident as ever, about my theory, about the items that control earth’s climatic system; in contrast to the laughable ,trace gas co2 theory, with a trace increase ,caused by man’s trace contribution, to the trace increase, of this trace gas, is somehow controlling earth’s climatic system. Next hoax, please. lol

  7. ALL:

    I computed an April 2011 average from the Discover website after interpolating the missing days at the end of the month, and compared it to April 2010 (which is the best way to get an estimate of the official anomaly), and I get 0.13 deg C lower (-0.01) than our official number (+0.12) which had the missing data included.

    Even considering the slightly different global-averaging strategy and missing days, though, this seems to be a rather large discrepancy. I’ve asked John if he has any ideas why….I’ll let you know what we find.


    Large month-to-month excursions are *usually* due to intraseasonal oscillations in the tropics, which alter the rate of heat exchange between the ocean and atmosphere. Thus, large 1-month changes are probably NOT due to radiative effects, but to convective effects.

    OH! I FORGOT!……
    The Discover website only shows Aqua AMSU ch. 5 (aka “T2” aka “TMT” aka “MT”) which has stratospheric influence…whereas we report the lower tropospheric (“LT”) retrieval in our monthly updates. The two are not the same…tangerines vs. oranges. Just one more reason to use the Discover site as just a rough guide.


  8. CatrunJ says:

    Oh Salvatore, my hero! I was hoping somebody could explain why the temperature went up again. I feel better that it is perfectly in line with your predictions of a decade of global cooling.

  9. Ray says:

    Bill Hunter,
    My feeble attempts to estimate the UAH anomaly from the AQUA CH5 anomaly are not intended to replicate the UAH figure, since I am aware that it is much more complicated than that. I don’t expect my figure to be identical to the UAH figure and only use it as a guide, as Dr. Spencer suggests.

  10. sillyfilly says:

    Dr. Spencer,

    Why don’t you publish the new baseline figure for your revised anomaly calculations. If not what’s the problem?

    Another counterpoint: given TSI and sunspots still at very low historical values and given that we are in a strong La Nina event (with some of the highest SOI values recorded),
    why is it that global temperatures seem unwilling to respond to these natural factors. Could it be that those bastions of low climate sensitivity of CO2 are failing to considerer that their calculations of sensitivity are far too low to explain the continuing long-term upward trend in temperature?

  11. CatrunJ says:

    To All:

    I saw this posted on dated May 5:

    “The actual RSS global temperature anomaly for April 2011 was .110 celsius above normal. By the way, March 2011 was slightly below normal at -.027 celsius.”

    The values reported here are .12 and -0.101.”

    So one could see this either as confirmation of a rise in global average temperature in April or proof of a vast conspiracy to fake the data in unison in order to hide the continuing global cooling.

  12. An Inquirer says:

    Let’s see if I understnad this correctly. Understandably, there were some missing #s on the Discover website. Both to determine the official anomaly and to guess the anomaly based on the graph on the Discover website, those missing #s have been interpolated.

    The daily current-year graph for channel 5 not only reflects the lower Troposhere, but also higher altitudes, including the Stratosphere. So the daily current-year graph could be quite immaterial when anticipating the official monthly anomaly. This official anomaly is only the lower Troposhere via AQUA, but there we (the public) never see the daily lower Troposphere #s.

    Meanwhile, we are not sure what the average is on the Discover website — whether it is a 20 year average, or a 30 year average; for lower Troposphere or for what altitude.


    I think I have just gained a lot more respect for the data on pro-CAGW government websites after these realizations of what we are seeing on the Discover website.

  13. Something puzzles me about these numbers. From February to March, both RSS and UAH went DOWN 0.08 C. However from March to April, RSS went UP 0.14, but UAH went UP 0.22. As we all know, a severe tornado hit Alabama at the end of April. Is it possible the missing days were interpolated wrongly?

  14. cementafriend says:

    Frankly, I do not believe the southern hemisphere figures. The March figure was -0.128 and then April jumped to +0.042? The Australian temperatures have been below normal and it appears we are headed for a cold winter. From what I have read South America also has had cold temperatures.

  15. Ray says:

    Living in England as I do, I can’t comment on the situation in Australia, but of course, the fact that it is colder than average there doesn’t mean the whole SH is colder.
    We have been experiencing above average temperatures in the UK, but we are only a small part of the NH.
    On the other hand, I DO find it difficult to believe that the entire NH has warmed by 0.272c, the SH by 0.17c and the entire globe by 0.22c, in a single month. I am suspicious in general of large fluctuations from month.

  16. cementafriend says:

    Maybe Dr Roy can answer but are the lower troposphere temperatures measured above cloud level. It has been cool in Australia because the sun has not been getting through the clouds. Steve Goddard has a post
    Maybe solar radiation is being absorbed by the clouds (droplets of water), some evaporation and convective mixing to increase air temperatures above the clouds. Of course the higher temperatures then lead to more radiation to space. Net effect should be cooling of the surface.

  17. An Inquirer says:

    It appears that the increase in SH temperatures from March to April was due to increased temperatures in the oceans — primarily in the South Pacific and India Ocean, and a little bit in the South Atlantic. Therefore, what Australia and South America have experienced in cool temperatures can be offset by the trend in ocean temperatures. (Also, Antarctica has had some temperatures warmer than usual.)

  18. DSmith says:

    The April anomaly seems high relative to the other data I see. It warrants a double check.


    I say, if the conditions I have outlined below take place, with the solar activity setting the tables for those items taking place below, due to a prolong solar minimum, that the temperatures this decade will be going down.

    The only questions I can see, is how long will the solar minimum last, and to what degree, and just how much influence will the solar minimum exert on the items I listed below. Those are the questions in my calculations , nevertheless, past history suggest, that a prolong solar minimum, will exert much influence, on the items listed below.



    1. SOLAR – solar flux reading below 100 ,for 90 % of the time, with spurts to 160.

    2. VOLCANIC- one or two eruptions with an explosive index of +5 this decade, along with a general increase of lesser eruptions.

    3. ATMOSPHERIC CIRCULATION -AO INDEX -1.5 or greater 60 % of the time.

    Two and Three tied into item one.

    4. MULTIVARIATE ENSO INDEX- avg. -1.0 c or more

    5. PDO/AMO -in cold phase -1.0c or more

    6.SOI index +20 or greater along with NINO3 SST INDEX -.5 C or greater.

    Again,if these factors materialize this decade, tied into the prolong solar minimum, temperatures are going down, despite the CO2 global man made warming theory. Prove me wrong.

  20. I suggest to one listen to the video Joe Bastardi,made today on the Weatherbell website ,that shows how wrong the global man made theory is . He talks about how the atm. hot spot, is missing in action ,and hence the more +AO will also be missing as a result of the former, and that rather, more cooling has been taking place aloft ,at 400mb /600mb ,as oppossed to the warming ,the pathetic global man made warming models have been forecasting.

    Hence atm. is becoming less stable, not more stable as the global warming models have suggested, and this in turn will also suggest less El Ninos ,as oppossed to the global warming models that suggest a greater occurrence.

    Anotherwords, the man made global warming CO2 theory and the models that support it are full of BS.

  21. pochas says:

    Just to add to the confusion, there have been several solar flares and CME’s recently. There are those who propose that such events can have a marked effect on earth’s weather. If nothing can be found wrong with the satellites, then the data is what it is.


    It turns out the stratosphere is responsible for the difference between the Discover ch 5 data and our official LT data. There was an abrupt switch from a westerly QBO to easterly last month, with strong lower stratospheric cooling in the tropics, which then influenced ch. 5.


    You are making too much out of month-to-month temperature variations. We have computed before that these large changes can be caused by less than 1% fluctuations in the convective heat transport from ocean to atmosphere.

    Stop thinking in terms of only radiation causing temperature changes.

  23. Dr. Spencer thanks for the valubale information on the QBO.

    I also agree that much to much is being made about the monthy temperatures. We need years to see where this is going or not going.

    Hope all is well. Take Care

  24. Ray says:

    Dr Spencer, thank you for the explanation of the difference between the CH5 and official figures for April.
    However, I am still slightly puzzled, since there is no obvious evidence of cooling in the April CH5 figures and in fact, the March CH5 anomaly was much lower than that for April.

  25. The last prolong solar minimum was the Dalton Minimum,1790-1840.

    Look at the geologic activity ,look at the temperature trends.

    Go back further to the Maunder Minimum,1610-1700. Look at the temp. trend /geological activity.

    Go back further ,to any prolong solar minimum, and the same results will be seen.

    I say this time will be no different, if we are indeed in a prolong solar minimum,which I believe we are.

  26. Bill Hunter says:

    cementafriend says: May 11, 2011 at 5:09 AM
    “Maybe Dr Roy can answer but are the lower troposphere temperatures measured above cloud level. . . .Maybe solar radiation is being absorbed by the clouds”

    When looking at the earth from space that would seem to be a likely liability to that method.

    Perhaps Dr Spencer can explain how problems there are avoided.

    Also, if he has time it would be nice at some point to post an update on the planet reflectivity data he did some time ago, along with updated sensitivity estimates. At that time they showed likely a good deal of warming in the past decade coming from negative cloud variation. Actually seeing how clouds were affected by the last El Nino and the current La Nina would be interesting.

    For all us climate watcher addicts a monthly report that shows what Dr Spencer describes above as variations in convective heat transport and clouds would help put the focus where he thinks it should be. Its high time somebody awards a grant to do that rather than continuing to proceed blindly pretending these things do not matter nor vary over the longterm.

  27. An Inquirer says:

    The confusion you mention apparently is due to the fact that the CH5 daily report on the Discover webpage IS NOT only the lower troposphere — despite the 14,000 ft / 600 mb description. Apparentlly the CH5 being reported also contains higher altitudes, including the stratosphere. I noticed over at RSS that the stratosphere cooled noticeably in April. Therefore, the April CH5 daily numbers are contaminated with the cooling anomaly in the stratosphere.

    The official UAH April anomaly strips out the information that contaminates the CH5 daily #. (BTW, I do not think that we really know what the average line actually is on the Discover webpage — what time period, whether it is AQUA, whether it contains contiminated data, whether it is adjusted for orbital decay, etc.) Therefore, at this point in time, it seems quite meaningless to follow the Discover webpage.

  28. Thank you Dr. Spencer. It is good to see you are back at work. Hope the bad weather of late will soon be just a bad memory for you, – at least. – For those in your community who lost a lot – or even for those who lost it all, we can only pray and hope for better times ahead.

    The bad weather that stuck Alabama and also (luckily for him) a few miles away from my nephew’s house in Carolina in the form of tornadoes has made me feel a bit silly, and I have asked myself this question: “Why do we, as AGW sceptics waste our time arguing amongst ourselves whether CO2 warms our planet – “just a little bit” – or “may be not at all” when what we should do is to unite in exposing the CAGW people’s fraud.

  29. Notice the silence from CATRUN J. TYPICAL OF THEIR SIDE

  30. Ray says:

    An Inquirer,
    Thanks for trying to help with my puzzlement over the CH5/UAH anomalies.
    The explanation given by Dr. Spencer for the apparent discrepancies between the UAH and CH5 anomalies,
    was that an abrupt switch from a westerly QBO to an easterly in April, which resulted in strong
    lower stratosphere cooling in the tropics, which in turn (by implication), reduced the CH5 anomaly.
    However, the actual CH5 figures show a warming trend during April (as is normal at this time of year),
    and while the anomalies did show a slight reduction during the middle of the month, they ended
    the month much higher than at the beginning of the month, and the months of February and March.
    On the other hand, the UAH anomalies for April show large increases globally and in the hemispheres,
    so I had assumed that the reason for the apparent discrepancy between the ch5 anomaly
    and the UAH anomaly was due to unusual warming of the troposphere, rather than cooling of the lower stratosphere, particularly since the latter apparently only occurred in the tropics.

  31. tom says:

    Meanwhile, this is the stuff James Hansen is saying when only the gullible are listening and real scientists are a hemisphere away:

  32. Ray says:

    Is there a reason why the AQUA Ch5 data haven’t been updated since May 5th?

  33. Ross says:

    This is simply not true. We are well into May now here in QLD Australia and it looks our temp. minimums are going up and up into the next week (after May 12th 2011)according to forecast estimates.

    I believe the world is not cooling. I do not believe in low sensitivity that mild AGW proponents do such as Roy Spencer.

    If these trends continue we are in for another shock warming trend for 2011. This is surprising considering we southerners are Winter whilst the Northers are in Summer.

    Presently clear skies have dominated QLD’s weather and the pattern of cooling at night is very insignificant. The La Nina- it is weakening at an alarming rate for Australia.
    I remember well the great freezing Winters in QLD in the 60’s when pipes froze and severe frost crop damage was widespread. God help Australia if a super El Nino returns to dominate – for us it means a diminishing rainfall.

    According to NOAA web site the pattern of ENSO have been leaning toward to more and more intense El Ninos.


    “Is the atmospheric/oceanic circulation changing?

    A rather abrupt change in the El Niño – Southern Oscillation behavior occurred around 1976/77.

    Often called the climatic shift of 1976/77, this new regime has persisted. There have been relatively more frequent and persistent El Niño episodes rather than the cool episode La Niñas. This behavior is highly unusual in the last 130 years (the period of instrumental record). Changes in precipitation over the tropical Pacific are related to this change in the El Niño – Southern Oscillation, which has also affected the pattern and magnitude of surface temperatures. However, it is unclear as to whether this apparent change in the ENSO cycle is related to global warming.”

  34. Ross, the PDO just went into the cold phase,expect many more La Ninas. The sun has just started it ‘s prolong solar minimum in late 2005. Geological activity has just begun to increase. The AO oscillation has recently started to be more negative. Amo’ will be going negative in a few years.

    What all this means is global cooling has been and will continue for the foreseeable future.

    You should take a look at the 600mb and 400mb tropospheric temp. this year and compare them to the last 10 years ,you will see how cold we have currently become.

  35. Ray says:

    I notice that the AQUA CH5 anomaly has now been updated on the discover website and is now above normal. Also there appears to have been at least one adjustment to previous individual daily figures.
    The cumulative ch5 anomaly at May 11th., was running at +0.08, which is equivalent to a UAH anomaly of about +0.14c.
    The NASA/GISS anomaly for April showed a slight fall from March, and is now nearer to the April UAH anomaly, so maybe it was the March satellite figures which were anomalous, not the April ones.

  36. craig says:

    CatrunJ’s posts have inspired me to ask a question that has always lingered.

    If i where to say that the past few months temp anomalies have shown it is no warmer (or colder) than it was since the base period and the base period may be as far back as the 50’s and 60’s.

    CatrunJ would respond by saying “aw gee shucks weather is not climate” and this statement would be true however, the fact still remains the present is still no warmer than 50 to 60 years ago which begs the question, whatever happened to global warming?

Leave a Reply