What is the long range weather forecast for Grants Pass, OR?

The Old Farmer's Almanac provides a 60-day extended weather forecast for Grants Pass, OR. This includes temperature trends, precipitation predictions, and seasonal weather patterns based on our traditional forecasting methods combined with modern meteorological science.

How accurate is the Almanac long range weather forecast?

The Old Farmer's Almanac claims an 80% accuracy rate for its long range forecasts. Our forecasting method uses a secret formula that considers sunspot activity, tidal action, and other factors along with current meteorological conditions.

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Long-Range Weather Forecast for Grants Pass, OR

Location Grants Pass, OR

60-Day Weather Forecast

August 2026 Long Range Weather Forecast for Pacific Northwest
Dates	Weather Conditions
Aug 1-5	Sunny, hot
Aug 6-21	Isolated t-storms, then sunny; warm
Aug 22-25	Scattered showers, cool
Aug 26-31	Sunny, turning hot
August	temperature 69° (2° above avg.) precipitation 0.5" (0.5" below avg.)

September 2026 Long Range Weather Forecast for Pacific Northwest
Dates	Weather Conditions
Sep 1-10	Sunny, very warm
Sep 11-17	Showers, then sunny; cool
Sep 18-30	Rainy periods, chilly
September	temperature 61° (1° below avg.) precipitation 4.5" (3" above avg.)

Map showing Old Farmer's Almanac long range weather region number 15

12-Month Long-Range Weather Outlook

November 2025 to October 2026

Winter will be warmer than normal, with the coldest periods in late November, early December, and early February. Precipitation and snowfall will be below average, with the snowiest period in early February. April and May will be cooler than normal in the north and warmer south. Precipitation will be below normal. Summer will be cooler and wetter than normal in the north, while southern areas will be hotter and drier than normal. The hottest periods will be in mid- and late July and early and late August. September and October will be cooler and wetter than usual.

See the complete 12-month weather forecast in The Old Farmer’s Almanac..

Weather Trend Graph

November 2025 to October 2026