Your nature year
Idaho Falls, Idahothrough the year
When do frost, green-up and fall color come to Idaho Falls?
For a day trip, Grand Teton is 64 miles off; its wildflowers is May 1–Sep 30 (local timing). For fall foliage, the nearest is Yellowstone (102 mi, Sep 1–Oct 31 (local timing)). Idaho Falls usually sees its last spring frost around May 9 and its first fall frost around Oct 1, a frost-free stretch of about 145 days at the nearest NOAA station, Idaho Falls - Kifi. About 5 weeks pass between first leaf and first bloom here. Leaves usually come out around Apr 14 and the first flowers around May 18. Head east for the closest of the 4 places we follow around Idaho Falls.
Updated Sep 27. Sources: US Census Bureau, 2024 Gazetteer (places) ↗ (opens in a new tab), US Census Bureau, city and town population estimates, 2024 ↗ (opens in a new tab), NOAA NCEI U.S. Climate Normals 1991–2020 (annual/seasonal) ↗ (opens in a new tab)
Idaho Falls's year at a glance
- Frost possible
- Frost-free, ~May 9 to ~Oct 1
- First leaf ~Apr 14
- First bloom ~May 18
- Today
Near Idaho Falls right now
- First fall frost usually around Oct 1 · last spring frost around May 9NOAA 1991–2020 normals, Idaho Falls - Kifi (2 mi, 50% dates)~3 days
- Yellowstone · 102 mi · Local timing: Sep 1–Oct 31Fall foliage · in its window now
- Lemhi Pass · 129 mi · Local timing: Sep 21–Oct 31Fall foliage · in its window now
Idaho Falls's nature year
- Spring green-upApr
- Wildflowers · Grand TetonNowMay–Sep
- Last spring frostMay
- Fall foliage · YellowstoneNowSep–Oct
- First fall frostOct
Nearby, season by season
Fall foliage
- Yellowstone · 102 miLocal timing: Sep 1–Oct 31
- Lemhi Pass · 129 miLocal timing: Sep 21–Oct 31
Wildflowers
- Grand Teton · 64 miLocal timing: May 1–Sep 30
- Craters of the Moon · 76 miusually Jun 1–30~8 months
- Yellowstone · 102 miLocal timing: Apr 1–Jul 31~6 months
Frost and green-up
Last spring frost
May 9
Average (50% date)
First fall frost
Oct 1
About 145 days without frost between
Spring green-up
Apr 14
First bloom around May 18
Frost: NOAA 1991–2020 climate normals at Idaho Falls - Kifi (2 mi from Idaho Falls), the day a 32 °F night is as likely as not. Green-up: the USA-NPN Spring Index, 1991–2020 average at the town.
Questions people ask
When is the first frost in Idaho Falls?
On average around Oct 1, and the last spring frost around May 9: about 145 days without frost between. These are NOAA's 1991–2020 normals at Idaho Falls - Kifi, 2 miles away (the day a 32 °F night is as likely as not).
When does spring green-up reach Idaho Falls?
The USA-NPN Spring Index puts first leaf around Apr 14 and first bloom around May 18, on average for 1991–2020 at the town.
Where can I see fall foliage near Idaho Falls?
Yellowstone, 102 miles (local timing: Sep 1–Oct 31); Lemhi Pass, 129 miles (local timing: Sep 21–Oct 31). Distances are straight-line.
Where can I see wildflowers near Idaho Falls?
Grand Teton, 64 miles (local timing: May 1–Sep 30); Craters of the Moon, 76 miles (usually Jun 1–30); Yellowstone, 102 miles (local timing: Apr 1–Jul 31). Distances are straight-line.
How we know
US Census Bureau, 2024 Gazetteer (places) (opens in a new tab) (Sep 27) · US Census Bureau, city and town population estimates, 2024 (opens in a new tab) (Sep 27) · NOAA NCEI U.S. Climate Normals 1991–2020 (annual/seasonal) (opens in a new tab) (Sep 27) · USA National Phenology Network, Spring Index 1991–2020 averages (opens in a new tab) (Sep 27)