Lepage Park

Rufus, John Day Lock and Dam, Lake Umatilla, Oregon

Tonight: low 46 °F, heavy dew.

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 August, typically 62°F. The coldest are in January, when 1 night in 10 drops to 19°F. Frost is common in January, February, March, November and December.

Typical nightCold night (1 in 10)
  1. Jan30°F 19°FBag comfortable to 20°F · frost 62% · rain or snow 44% of days
  2. Feb30°F 21°FBag comfortable to 20°F · frost 64% · rain or snow 41% of days
  3. Mar35°F 28°FBag comfortable to 30°F · frost 30% · rain or snow 33% of days
  4. Apr41°F 33°FBag comfortable to 35°F · frost 7% · rain or snow 25% of days
  5. May48°F 41°FBag comfortable to 40°F · frost 0% · rain or snow 17% of days
  6. Jun55°F 48°FBag comfortable to 50°F · frost 0% · rain or snow 8% of days
  7. Jul62°F 55°FBag comfortable to 55°F · frost 0% · rain or snow 3% of days
  8. Aug62°F 55°FBag comfortable to 55°F · frost 0% · rain or snow 4% of days
  9. Sep (this month)55°F 48°FBag comfortable to 50°F · frost 0% · rain or snow 10% of days
  10. Oct45°F 38°FBag comfortable to 40°F · frost 3% · rain or snow 26% of days
  11. Nov37°F 29°FBag comfortable to 30°F · frost 21% · rain or snow 40% of days
  12. Dec31°F 22°FBag comfortable to 25°F · frost 57% · rain or snow 46% 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 lookFriday, September 25, 10 p.m. to 7 a.m.

Cold air collects in this hollow

Your setup looks borderline for this night

You may feel chilly from around 6 a.m.

Your spot sits in a hollow where cold air collects at night.

Best change

Move 20 to 50 meters higher, away from the valley floor or creek.

  • On clear, calm nights it is often several degrees warmer there.

This is based on typical values for the gear types you picked, so treat it as an estimate.

  • Low outside46°F
  • Moistureheavy dew, bring everything inside
  • Windcalm

Your night

  1. 10 p.m. to 6 a.m.ComfortableAir around you 60 to 43°F, heavy dew from 5 a.m.
  2. 6 a.m. until morningChilly. Add a layerAir around you 40 to 39°F, heavy dew.
Every hour
  • 10 p.m.60°Fcomfortable
  • 11 p.m.59°Fcomfortable
  • midnight57°Fcomfortable
  • 1 a.m.54°Fcomfortable
  • 2 a.m.53°Fcomfortable
  • 3 a.m.52°Fcomfortable
  • 4 a.m.51°Fcomfortable
  • 5 a.m.43°Fcomfortable, heavy dew
  • 6 a.m.40°Fchilly, heavy dew
  • 7 a.m.39°Fchilly, heavy dew

This spot sits about 44 m below the land around it. On clear, calm nights cold air pools here, so expect it colder and wetter than the forecast.

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 35°F or colder

    Usually sold as a 26° 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.

Before you sleep

  • Put on a warm layer and a hat before about 6 a.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.
  • Your spot sits lower than the ground around it. On a clear, calm night cold air drains into spots like this, so expect it colder and wetter than the forecast. If you can, move a little higher up, away from the creek or valley floor.
  • 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 (7 a.m.):

Outside at your spot
46°F
Warmth your shelter holds
+2 °F
Clear-sky cooling
−2 °F
Low spot
−7 °F
Air around you
39°F
Your bag's comfort rating
39°F
Cold ground through what you lie on
+4 °F
Your comfort limit
43°F

4 °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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