Climate Monitor
How the country has run against normal, what it means for heating and cooling demand, where CPC thinks the next weeks and months are headed, and how its last outlooks scored.
Temperature & precipitation departures
How the U.S. has run compared with the 1991–2020 normals, from station data analyzed by the High Plains Regional Climate Center's ACIS maps. Each map prints its own date range in the title; they're rebuilt daily and run a day or two behind, so the "month to date" map still shows the previous month for the first day or two of a new month.
For a season-to-date view, "Last 3 months" covers the three most recent complete months (it lines up with a meteorological season on the 1st of Mar, Jun, Sep and Dec), and "Last 90 days" is a rolling window. HPRCC doesn't publish a meteorological-season-to-date map, so neither is labeled that way here. The water year starts October 1. Data are provisional.
Degree days
Heating degree days (HDD) add up how far each day's mean temperature falls below 65°F, and cooling degree days (CDD) how far it rises above. They track heating and cooling demand. These are the Climate Prediction Center's weekly population-weighted totals, which count heavily populated areas more. In the HDD table, blue means more heating demand than normal (colder) and orange means less. In the CDD table, orange means more cooling demand (hotter).
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Source: CPC degree-day statistics (weekly state, regional and national summaries, updated weekly). HDD seasons run from July 1 and CDD seasons from January 1.
CPC outlooks
The Climate Prediction Center's official outlooks show the probability that temperature or precipitation will be above, near or below normal for the period. Shading shows the most likely category and how confident CPC is. White "EC" (equal chances) areas mean no category is favored. They show odds, not amounts. The 6–10 and 8–14 day outlooks are issued every afternoon. The monthly outlook is first issued around the third Thursday of the month and updated on its last day, and the seasonal outlooks come out with the mid-month monthly issue.
The valid period is printed on each map. More leads, out to 13 months, are on CPC's seasonal page. ENSO and MJO context lives on the Teleconnections page.
How did CPC's outlooks do?
CPC grades each outlook once the period is over, putting its forecast map beside the observed category map and scoring it with the Heidke skill score (HSS). On the HSS, 0 is no better than chance, 100 is perfect and negative is worse than chance. "Non-EC" scores count only the areas where CPC made a call. These are the latest verifications CPC has posted.
Monthly ·
Seasonal ·
Sources: CPC monthly and seasonal verification, and the CPC verification summary. Verification posts a few weeks after each period ends. To learn to read these charts, see the Weather 101 chart guides.