Summerville Weather Forecast
- 41
- 66
Rain Showers
- 41
- 71
Becoming Sunny
- 44
- 80
Sunny
- 45
- 85
Sunny
- 46
- 83
Partly Sunny
- 48
- 84
Partly Sunny
- 49
- 83
Partly Sunny
Today 14 Sep Grande Ronde Valley
A chance of rain Showers in the Morning, then rain Showers likely and a chance of Thunderstorms in the afternoon. Highs in the mid to upper 60s. Northwest wind 5 to 10 Mph in the Morning, becoming light. Chance of precipitation 70 percent. Rainfall Amounts up to a half of an inch Possible, except higher Amounts possible in Thunderstorms.
Tonight 14 Sep Grande Ronde Valley
Mostly cloudy. Rain Showers likely and a chance of Thunderstorms in the Evening, then a chance of rain Showers overnight. Lows in the lower 40s. South wind 5 to 10 Mph. Chance of precipitation 60 percent. Rainfall Amounts less than a quarter of an Inch, except higher Amounts possible in Thunderstorms.
Summerville Temperature Statistics
September Temperature
La Grande/Union County Airport (13 miles)
Lowest 7 September, 2025
48 °FAverage September
69.5 °FHighest 2 September, 2025
100.9 °F
Climate (2020–Present)
La Grande/Union County Airport (13 miles)
Average Low 2020–2025
37.9 °FAverage 2020–2025
50.2 °FAverage High 2020–2025
62.3 °F