National Climate Report - Annual 2015
Regional Warmest and Wettest Years

« National Climate Report - Annual 2015


Regional Warmest and Wettest Years


The year 2015 was the 2nd warmest of the 121 on record, when temperatures are averaged across the contiguous United States (CONUS). The warmest year on record for the CONUS remains 2012. However, not all places within the CONUS had their warmest year in 2012. Places have unique climate histories, including the local and regional "warmest year on record".

The top map below shows the local warmest year on record across the CONUS for average temperature. The five largest footprints are depicted in unique colors; the other years are combined into an "other" category. The other three maps depict the same type of analysis, for: minimum ("overnight low") temperature, maximum ("afternoon high") temperature, and precipitation.

Looking at the average temperature map and associated table, it is interesting to note which years are not represented. 2012 featured record warmth across the nation's midsection, and shows up prominently. However, 2015 — the 2nd warmest year on record — had relatively little area that was record warm. Its high national ranking was driven by broad coverage of much-warmer-than-normal — but not quite record warm — conditions. In contrast, 2014 has the 3rd largest footprint of record-warm temperatures, but ranks only 36th warmest for the overall CONUS average, because its record temperatures in the West were counterbalanced by quite cool annual temperatures in the Midwest and Mississippi Valley.

The maximum temperature map and tables are dominated by drought years. Intense, large-footprint droughts dominated nearly every year listed in the table. High temperatures tend to be even higher during times of drought, because the sun's energy goes disproportionately into heating the surface versus evaporating water. The minimum temperature map includes 2015 occupying the 3rd largest area. Precipitation is highly variable compared to temperature, so the regions depicted for "wettest year on record" are smaller and much more fractured than those for temperature.

(click any image to enlarge)

Average Temperature

YearExtent
201234.6%
193420.0%
20148.9%
19877.4%
19986.0%
19215.6%
20154.2%
19902.8%
19272.3%
19331.6%
map depicting local warmest TAVG year on record

Minimum Temperature

YearExtent
199827.5%
201214.1%
193411.4%
201410.3%
20159.9%
19876.7%
19001.7%
19221.5%
19211.4%
19331.3%
map depicting local warmest TMIN year on record


Maximum Temperature

YearExtent
201232.2%
193424.4%
19218.1%
19875.7%
19904.9%
20144.6%
19983.2%
20152.6%
19312.5%
19271.6%
map depicting local warmest TMAX year on record


Precipitation

YearExtent
194110.6%
19837.8%
20115.8%
19153.9%
19963.6%
19933.5%
19053.3%
20152.9%
19732.6%
19572.3%
map depicting local wettest year on record