Big Springs Grp. Area - Island Park
Tonight: low 43 °F, calm and dry.
Nights by month
Night lows from 2016 to 2025: a typical night, and the cold one that comes 1 night in 10.
The mildest nights are in July, typically 51°F. The coldest are in December, when 1 night in 10 drops to 0°F. Frost is common in January, February, March, April, May, October, November and December.
- Jan12°F -1°FBag comfortable to 0°F · frost 100% · rain or snow 47% of days
- Feb13°F 1°FBag comfortable to 0°F · frost 100% · rain or snow 55% of days
- Mar19°F 9°FBag comfortable to 10°F · frost 98% · rain or snow 44% of days
- Apr25°F 14°FBag comfortable to 15°F · frost 90% · rain or snow 42% of days
- May32°F 25°FBag comfortable to 25°F · frost 50% · rain or snow 39% of days
- Jun42°F 34°FBag comfortable to 35°F · frost 6% · rain or snow 31% of days
- Jul51°F 44°FBag comfortable to 45°F · frost 0% · rain or snow 14% of days
- Aug50°F 44°FBag comfortable to 45°F · frost 0% · rain or snow 18% of days
- Sep (this month)42°F 33°FBag comfortable to 35°F · frost 8% · rain or snow 23% of days
- Oct31°F 14°FBag comfortable to 15°F · frost 55% · rain or snow 36% of days
- Nov17°F 6°FBag comfortable to 5°F · frost 91% · rain or snow 40% of days
- Dec12°F 0°FBag comfortable to 0°F · frost 99% · rain or snow 48% of days
| = 32°F
History: ERA5 and ERA5-Land reanalysis via Open-Meteo, corrected to the site's elevation. Bag rating: the comfort rating that keeps you warm in a tent on 9 of 10 nights that month.
Tonight
Good nightFriday, September 25, 10 p.m. to 7 a.m.
Your selected gear looks warm enough
About 5 °F to spare at the coldest hour.
This is based on typical values for the gear types you picked, so treat it as an estimate.
Your night
- 10 p.m. until morningComfortableAir around you 61 to 44°F.
Every hour
- 10 p.m.60°Fcomfortable
- 11 p.m.61°Fcomfortable
- midnight60°Fcomfortable
- 1 a.m.59°Fcomfortable
- 2 a.m.54°Fcomfortable
- 3 a.m.50°Fcomfortable
- 4 a.m.48°Fcomfortable
- 5 a.m.46°Fcomfortable
- 6 a.m.45°Fcomfortable
- 7 a.m.44°Fcomfortable
Times are local time at your spot (GMT-6).
What works tonight
The gear this night calls for, for someone who sleeps like you.
- You have this
Sleeping bag
Comfort 40°F or colder
Usually sold as a 31° bag. The number in a bag's name is the limit, not the comfort.
- You have this
Underneath you
R1.5 or more
The R-value says how well a pad keeps the cold ground out.
How we estimated this
At the coldest hour (7 a.m.):
- Outside at your spot
- 43°F
- Warmth your shelter holds
- +2 °F
- Clear-sky cooling
- −1 °F
- Air around you
- 44°F
- Your bag's comfort rating
- 39°F
- Your comfort limit
- 39°F
5 °F to spare, so warm enough.
Assumptions
- Bag categories use typical ratings as sold: summer about 50 °F (10 °C), 3-season about 30 °F (-1 °C), winter about 15 °F (-9 °C). The number in a bag's name is usually its lower limit, so its comfort rating is about 9 °F (5 °C) warmer.
- What you lie on: foam mat about R2, thin air pad about R1.5, insulated pad about R3.5, winter pad R5 and up, van bed about R4, air mattress about R0.5. Colder ground needs a higher R-value.
- Shelters hold a few degrees early in the night and less towards morning. Wind and clear, calm skies take warmth away.
- Weather: Open-Meteo forecast for your spot, on a grid of a few kilometers, corrected to its height.
- These are rules of thumb, not measurements. People and gear vary.
A forecast, not a promise. Mountains, valleys and water make their own weather, so trust what you see and feel on site. Terms and liability
Checked for a double-wall tent, a 3-season bag and a thin air pad. Check your own gear here.
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