YR MON GLOBE NH SH TROPICS
2009 1 0.251 0.472 0.030 -0.068
2009 2 0.247 0.565 -0.071 -0.045
2009 3 0.191 0.324 0.058 -0.159
2009 4 0.162 0.315 0.008 0.012
2009 5 0.139 0.161 0.118 -0.059
2009 6 0.041 -0.021 0.103 0.105
2009 7 0.429 0.190 0.668 0.506
2009 8 0.242 0.236 0.248 0.406
2009 9 0.505 0.597 0.413 0.594
2009 10 0.362 0.332 0.393 0.383
2009 11 0.498 0.453 0.543 0.479
2009 12 0.284 0.358 0.211 0.506
2010 1 0.648 0.860 0.436 0.681
2010 2 0.603 0.720 0.486 0.791
2010 3 0.653 0.850 0.455 0.726
2010 4 0.501 0.799 0.203 0.633
2010 5 0.534 0.775 0.292 0.708
2010 6 0.436 0.550 0.323 0.476
2010 7 0.489 0.635 0.344 0.422


The global-average lower tropospheric temperature remained high, +0.49 deg. C in July, 2010, although the tropics continued to cool as La Nina approaches.

As of Julian Day 212 (end of July), the race for warmest year in the 32-year satellite period of record is still too close to call with 1998 continuing its lead by only 0.07 C:

YEAR GL NH SH TRPCS
1998 +0.62 +0.73 +0.51 +0.90
2010 +0.55 +0.74 +0.36 +0.63

To exceed 1998 as the warmest year, the daily global average temperature for the remainder of this year (1 Aug to 31 Dec, 2010) will need to average above +0.466 deg. C.

As a reminder, five months ago we changed to Version 5.3 of our dataset, which accounts for the mismatch between the average seasonal cycle produced by the older MSU and the newer AMSU instruments. This affects the value of the individual monthly departures, but does not affect the year to year variations, and thus the overall trend remains the same as in Version 5.2. ALSO…we have added the NOAA-18 AMSU to the data processing in v5.3, which provides data since June of 2005. The local observation time of NOAA-18 (now close to 2 p.m., ascending node) is similar to that of NASA’s Aqua satellite (about 1:30 p.m.). The temperature anomalies listed above have changed somewhat as a result of adding NOAA-18.

[NOTE: These satellite measurements are not calibrated to surface thermometer data in any way, but instead use on-board redundant precision platinum resistance thermometers (PRTs) carried on the satellite radiometers. The PRT’s are individually calibrated in a laboratory before being installed in the instruments.]