As part of our United States Best Places report, we analyzed high temperature forecast accuracy for one to three days in advance. A forecast was deemed accurate if it was within three degrees of the observed high temperature.
The most accurate high temperature forecasts were found in Florida, Hawaii, Puerto Rico, and southern Arizona. Other areas near water, such as the remainder of the west coast, most of the east coast, and near the southern Great Lakes also had high temperature accuracy of 80% or greater. The least accurate high temperature forecasts were found in the central to northern Plains, northern Rockies, and much of Alaska.
When we compare the high temperature forecast accuracy to our previous report in 2023, there were slight improvements in accuracy in small, scattered areas along the central California coast and from eastern Montana southeast to western Tennessee. However, small declines in forecast high temperature accuracy was more common, and most prominent in areas such as southeast Oregon to northwest Wyoming and southeast to central Texas and western Arkansas. The weather providers we analyzed did not change between the two reports, and much of the changes in accuracy were very likely the result of typical annual weather variability.
Out of the 832 locations we analyzed, the top ten most accurate cities were all located either in/near the tropics or near large bodies of water. In these areas, tropical air masses prevail, and temperatures naturally do not vary much due to consistently high sun angles and the large heat capacity of water.
Ceiba, Puerto Rico had exceptionally good forecasts, with 97.1% of one to three day out high temperature forecasts within 3F of the actual observed high. 94% of its persistence forecast high temperatures were also within the same threshold. This is the place you want to go to have consistent, easily predictable weather!
Seven of the ten locations with the least accurate high temperature forecasts were in Alaska, and the other three are in the northern Great Plains. In those areas of Alaska, cities and villages are widely spread with little to no road networks and few flights that travel over the region. There is little in the way of atmospheric observations at ground level or above, which makes forecasting very challenging.
Check out our full report at https://forecastwatch.com/services/best-places-reports/.