Grasshopper Campground (MT)
Tonight: low 33 °F, frost likely, breezy.
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 44°F. The coldest are in December, when 1 night in 10 drops to -5°F. Frost is common in January, February, March, April, May, June, September, October, November and December.
- Jan8°F -3°FBag comfortable to 0°F · frost 100% · rain or snow 36% of days
- Feb8°F -6°FBag comfortable to -5°F · frost 100% · rain or snow 53% of days
- Mar13°F 2°FBag comfortable to 5°F · frost 100% · rain or snow 42% of days
- Apr18°F 7°FBag comfortable to 5°F · frost 99% · rain or snow 46% of days
- May27°F 19°FBag comfortable to 20°F · frost 83% · rain or snow 46% of days
- Jun34°F 24°FBag comfortable to 25°F · frost 36% · rain or snow 41% of days
- Jul44°F 36°FBag comfortable to 35°F · frost 2% · rain or snow 29% of days
- Aug43°F 36°FBag comfortable to 35°F · frost 2% · rain or snow 25% of days
- Sep36°F 26°FBag comfortable to 25°F · frost 30% · rain or snow 28% of days
- Oct24°F 8°FBag comfortable to 10°F · frost 80% · rain or snow 34% of days
- Nov (this month)12°F 0°FBag comfortable to 0°F · frost 98% · rain or snow 35% of days
- Dec7°F -5°FBag comfortable to -5°F · frost 99% · rain or snow 44% 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
Worth a lookMonday, November 9, 10 p.m. to 7 a.m.
Your setup looks too cold for this night
Expected from around 10 p.m.
Your sleeping bag is not warm enough for this night.
Best change
Sleep in a warm layer, a hat and dry socks, and take a hot water bottle.
This is based on typical values for the gear types you picked, so treat it as an estimate.
Your night
- 10 p.m. to 4 a.m.Chilly. Add a layerAir around you 42 to 36°F, frost from 3 a.m., gusty from midnight (up to 25 mph).
- 4 a.m. to 5 a.m.Cold. Your setup is not warm enoughAir around you 34°F, frost.
- 5 a.m. to 6 a.m.Chilly. Add a layerAir around you 35°F.
- 6 a.m. to 7 a.m.Cold. Your setup is not warm enoughAir around you 34°F, frost.
- 7 a.m. until morningChilly. Add a layerAir around you 35°F.
Every hour
- 10 p.m.42°Fchilly
- 11 p.m.41°Fchilly
- midnight39°Fchilly, gusty
- 1 a.m.38°Fchilly, some dew
- 2 a.m.38°Fchilly, some dew
- 3 a.m.36°Fchilly, frost
- 4 a.m.34°Fcold, frost
- 5 a.m.35°Fchilly
- 6 a.m.34°Fcold, frost
- 7 a.m.35°Fchilly
Times are local time at your spot (GMT-7).
What works tonight
The gear this night calls for, for someone who sleeps like you.
- Missing
Sleeping bag
Comfort 30°F or colder
Usually sold as a 21° bag. The number in a bag's name is the limit, not the comfort.
- Missing
Underneath you
R2.5 or more
The R-value says how well a pad keeps the cold ground out.
- Worth adding
Also useful
A bag liner
Adds a few degrees to the bag you already own.
Before you sleep
- Put on a warm layer and a hat before about 10 p.m., or go to bed already wearing them.
- Eat a proper meal with some fat before bed. Your body keeps burning it through the night.
- Pee right before you get in your bag. Getting out at 3 a.m. in the cold is worse.
- Sleep in dry clothes, not the ones you wore all day. Damp fabric pulls heat out of you.
- Fill a sturdy water bottle with hot (not boiling) water, check the lid does not leak, and put it in your bag by your core or feet.
- Stake out every guyline and point the low, narrow end of the tent into the wind.
- Bring shoes, clothes and electronics inside. Anything left out will be wet by morning.
- Open the tent vents and keep the door zip open a bit at the top. Some condensation inside is normal on a night like this, so bring a small towel to wipe it off.
How we estimated this
At the coldest hour (6 a.m.):
- Outside at your spot
- 33°F
- Warmth your shelter holds
- +2 °F
- Clear-sky cooling
- −1 °F
- Air around you
- 34°F
- Your bag's comfort rating
- 39°F
- Cold ground through what you lie on
- +4 °F
- Your comfort limit
- 43°F
9 °F short, so you will likely be cold.
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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