Warm May expected for U.S.
The U.S. temperature outlook for May 2025, showing where the monthly temperature is favored to be much warmer than average (orange and red) or much cooler than average (blues). Darker colors mean higher chances, not more extreme temperatures. White areas mean that there are equal chances for a warm, cool, or near-average May. Much warmer or much cooler than average means "in the upper or lower third" of average May temperatures from 1991-2020.
National Oceanic and Atmospheric Administration – Above average temperatures are forecast across much of the United States through May, including most of the northern, central and eastern parts of the nation, as well as southern Alaska, reported the NOAA’s Climate Prediction Center in its monthly outlook released April 30.
The temperature outlook favours well above average temperatures across much of the country, including most of the northern, central, and eastern parts of the nation, as well as southern Alaska. Below-average temperatures are not favoured anywhere, with all outcomes (cool, warm or near-normal) equally likely along the West Coast, in the Southwest and across much of Alaska.
The greatest odds (50 to 60 per cent) for warmth are found in the northern Plains, where temperatures during the month look to begin well above average. Elsewhere over the nation, odds are generally 40 to 50 per cent, with temperatures generally favored to be above average during the six to 10 day, Week 2, and Weeks 3 and 4 outlooks, particularly across the northern and central parts of the country.
Areas with more uncertainty (those areas with an “equal chance” forecast) are favored to experience below-normal temperatures during the first half of the month. However, with above-average temperatures favored in the Weeks 3 to 4 outlook for most of these regions, confidence in these regions experiencing a colder-than-average May was quite low, so “equal chances” is the forecast.
With upwards of 75 millimetres of rain predicted to fall in the Texas Panhandle during the first week of May, and above-average rainfall favored in this region in all other CPC outlooks, the May precipitation outlook has relatively high probabilities exceeding 60 per cent for this region. Probabilities favoring above-average rainfall in the remainder of the Southern and parts of the Central Plains are lower, as the Weeks 3 to 4 precipitation outlook for this region is uncertain (equal chances). Odds also favor above-average rainfall in the interior West, with expected rainfall during the first week of May potentially approaching typical monthly values.
In contrast, below-normal precipitation is favored over parts of the Northern Plains, around the Great Lakes and in the Ohio Valley, as ridging (jet stream shifted north of normal) is expected to dominate the northern tier of the U.S. during much of the month.
Heavy rain caused total drought coverage across the country to decrease from close to 45 per cent to about 37 per cent during April. The percent of the country in the two most intense categories (D3 and D4, representing extreme and exceptional drought) did increase slightly, however, from about eight per cent to over nine per cent.
With above-normal precipitation favored in the Southern and Central Plains, drought improvement with some removal is likely there during May. Drought improvement is also likely in parts of Nevada, where the monthly outlook favors above-average precipitation. Drought persistence is most likely in the remainder of the West, despite some regions having a slight tilt in the odds toward above-average rainfall, as well as the Northern Plains and the Southeast.
Finally, drought improvement with some removal is likely in the mid-Atlantic and Northeast, with the potential for significant amounts of rainfall falling during the first week of May.
