NOAA temperature drop
In April, 2020, the Northern Hemisphere experienced its 2nd largest 2-month drop in temperature in the 497-month satellite record.

The Version 6.0 global average lower tropospheric temperature (LT) anomaly for April, 2020 was +0.38 deg. C, down from the March, 2020 value of +0.48 deg. C.

The Northern Hemisphere temperature anomaly fell from +0.96 deg. C to 0.43 deg. C from February to April, a 0.53 deg. C drop which is the 2nd largest 2-month drop in the 497-month satellite record. The largest 2-month drop was -0.69 deg. C from December 1987 to February 1988.

The linear warming trend since January, 1979 has now increased to +0.14 C/decade (but remains statistically unchanged at +0.12 C/decade over the global-averaged oceans, and +0.18 C/decade over global-averaged land).

Various regional LT departures from the 30-year (1981-2010) average for the last 16 months are:

NOAA temperature drop
The UAH LT global gridpoint anomaly image for April, 2020 should be available within the next week here.

The global and regional monthly anomalies for the various atmospheric layers we monitor should be available in the next few days at the following locations:

Lower Troposphere: http://vortex.nsstc.uah.edu/data/msu/v6.0/tlt/uahncdc_lt_6.0.txt
Mid-Troposphere: http://vortex.nsstc.uah.edu/data/msu/v6.0/tmt/uahncdc_mt_6.0.txt
Tropopause: http://vortex.nsstc.uah.edu/data/msu/v6.0/ttp/uahncdc_tp_6.0.txt
Lower Stratosphere: http://vortex.nsstc.uah.edu/data/msu/v6.0/tls/uahncdc_ls_6.0.txt

Source: Dr. Roy Spencer

From the Alabama State Climatologist, Dr. John Christy:

Global Temperature Report: April 2020

Global Temperature Report: April 2020
Global climate trend since Dec. 1 1978: +0.135 C per decade
Global climate trend since Dec. 1 1978: +0.135 C per decade
April Temperatures (preliminary)

Global composite temp.: +0.38 C (+0.68 °F) above seasonal average
Northern Hemisphere: +0.43 C (+0.77 °F) above seasonal average
Southern Hemisphere: +0.34 C (+0.61 °F) above seasonal average
Tropics: +0.45 C (+0.81°F) above seasonal average

March Temperatures (Final)

Global composite temp.: +0.48 C (+0.86 °F) above seasonal average
Northern Hemisphere: +0.61 C (+1.10 °F) above seasonal average
Southern Hemisphere: +0.34 C (+0.61 °F) above seasonal average
Tropics: +0.63 C (+1.13°F) above seasonal average

Notes on data released May 1, 2020 (v6.0)

Seasonally-adjusted temperatures dropped a bit in the tropics and northern hemisphere from March values leading to a global temperature departure from average of +0.38 °C (+0.68 °F). As indicated last month we suggested that the drop is due in part to the cooling of the central Pacific Ocean. Recall that in the latter months of 2019, a weak, warm El Niño like event occurred which aided in warming up the atmosphere for a few months but that impact is mostly exhausted now. The two-month drop in the Northern Hemisphere temperature of -0.53 °C is rare - exceeded only once in the 497-month history when the hemisphere cooled between the 1987 warm El Niño and the cold 1989 La Niña. The NH temperature dropped -0.69 °C between December 1987 and February 1988.

The region with the warmest departure from average was a large hot spot in central Russia in the Krasnoyarsk Krai region. The peak occurred near Vorogovo at a remarkable +6.4 °C (+11.4 °F) above average. As is usual, when it's very warm in one place, there are usually a series of alternating cold and warm regions in the same latitude belt, reflecting a somewhat stationary pattern. This month the pattern indicates three warm peaks (Central Russia, Gulf of Alaska and Europe) with three cool areas in between (Sea of Japan, Canada and western Russia.) Moving eastward from the peak in central Russia to the cool area in central Canada we find the coldest departure from average near the Prince Albert National Park in Saskatchewan with a -3.3 °C (-6.0 °F) anomaly.


Comment: This unseasonable warmth in the Russian Far East appears to have had some knock on effects: Wildfires critical in Siberia and Russian Far East, follow 'abnormally warm winter and arid spring'


Besides the locations mentioned above, warmer than average conditions prevailed in the Caribbean Sea, Eastern Antarctica and western Australia. Cooler than average temperatures were found in the southern oceans.

The conterminous U.S. experienced its coolest April since 1998 being -0.59 °C (-1.06 °F) below the seasonal average. April U.S. temperatures have a large range though, being as cool as -2.54 °C (1983) and as warm as +2.08 °C (1981). Alaska was warmer than average in April, so that the 49-state mean temperature departure was not quite as cold as the 48-state value being -0.24 °C (-0.43 °F). [We don't include Hawaii in the US results because its land area is less than that of a satellite grid square, so it would have virtually no impact on the overall national results.]

The remarkable warmth of the lower stratosphere that was linked to the aerosols from the Australian fires last year is apparently fading. The global departure from average for this layer was +0.00 °C in April, down from +0.32 °C last month. Even so, April's temperature was the warmest since the volcanically-induced warming in 1993 after the eruption of Mt. Pinatubo in 1991.
Source: https://www.nsstc.uah.edu/climate/