Grand Teton Forecast Monday – Tuesday 20-21 September

  • Short-term forecast, emphasizing weather parameters most important to visitors in the Jenny Lake / String Lake / Leigh Lake region
  • Animations of expected weather radar updated daily.
    • Other weather parameters (snow, wind, etc.) added when they may be significant.
    • For orientation, animation maps show Wyoming and a small portion of the surrounding states.
  • Temperature graphic is for the Airport. Subtract a couple of degrees for String Lake and 3-5 degrees if a visitor asks about Colter Bay.
  • The wind gusts forecasts are usually (in the summer) a reasonable forecast for average sustained wind speeds at 9,000 – 11,000 feet for backcountry hikers.
  • For those with access to Grand Teton Park Radios: Channel 16 is NOAA Weather Radio
  • Click here for access to the NOAA smoke-forecasting site.
  • Click here for an animation of smoke concentration over the northwest U.S. for the next two days.

Hard freeze Monday night, then the warmup begins…

Monday: Mostly cloudy in the morning with rain showers and snow showers tapering off early morning, then variable cloudiness with rain and snow showers re-developing in the afternoon. Most showers will be north of Colter Bay. Wind gusts 12-18 mph. Some roads may be icy Monday morning. Cold, with high temperatures around 50 deg.

Tuesday: Partly to mostly sunny. Expect a hard freeze by Tuesday morning with lows in the lower 20’s. Highs in the lower 60’s.

Smoke forecast: Light smoke Monday morning, but Grand Teton should be free of wildfire smoke by Monday afternoon and remain that way on Tuesday.

Extended Outlook:

Wednesday – Thursday: Partly to mostly sunny and milder. Highs in the mid to upper 60’s.

Friday – Sunday: Partly to mostly sunny and warmer. Highs in the low 70’s.

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