official data
CPC rewrites September: heat shifts east, West cools
The Climate Prediction Center issued an updated September 2026 30-day outlook discussion at 3:00 PM EDT on Monday, 31 August 2026. CPC says there are considerable temperature changes versus the mid-month outlook: troughing is forecast to impact much of the western CONUS early in the month, so cooler conditions are now expected there, while the area of favored above-normal temperatures shifts eastward to the central U.S., Great Lakes, and mid-Atlantic. The highest likelihood for above-normal temperatures is over the central Great Plains, where GEFS and ECMWF guidance predict strong ridging in the first ~10 days of September plus substantially below-normal surface wetness. Forecaster: Jon Gottschalck. Normals: 1991–2020.
Key facts
- Issued
- 3:00 PM EDT Mon Aug 31, 2026 — updated Sep 2026 30-day outlook
- Temperature shift
- West cooler (early-month troughing); above-normal heat shifted east to central U.S., Great Lakes, mid-Atlantic
- Highest heat odds
- Central Great Plains — strong ridging first ~10 days of September + dry soils
- Precipitation
- Above-normal still favored CA/Intermountain West/Southwest; Pacific Northwest now wetter; below-normal tilt central Plains/central Mississippi Valley under amplified ridging
- Forecaster / next
- Jon Gottschalck; next monthly outlook for Oct on Thu Sep 17, 2026
- Normals
- 1991–2020
There are considerable changes in the updated temperature outlook from the mid month outlook.
NWS CPC Prognostic Discussion for Monthly Outlook, Aug 31, 2026
Note
CPC’s updated discussion is primarily informed by model guidance across short-, medium-, extended-, and subseasonal-range forecasts, with near-coast SSTs and surface wetness anomalies adjusting the outlook in some areas.
This note summarizes the official Aug 31 discussion only. It does not invent drought maps, county lists, or temperature thresholds beyond what CPC published.
Why it matters
Material Aug 31 CPC rewrite of the full September monthly outlook — distinct from the week-2 heat/drought hazards item. Official seasonal guidance, not a Doom Signals forecast.
Sources
Official data. Not a forecast.