Your nature year
Iowa City, Iowathrough the year
When do frost, green-up and fall color come to Iowa City?
Frost usually lets go around Apr 21 and comes back around Oct 18, according to the nearest NOAA station, Iowa City Municipal Airport: roughly 180 days without it. Spring green-up reaches town around Apr 5, with first blooms around May 2.
Spring takes about 4 weeks to go from leaf to bloom. Head southeast for the closest of the 4 places we follow around Iowa City. The closest place we follow is Port Louisa Refuge, 37 miles away, for spring migration, April to May (local timing). Emiquon Refuge (118 mi) is the pick for winter wildlife, migration typically peaks in November (usually).
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)
Near Iowa City right now
- First fall frost usually around Oct 18 · last spring frost around Apr 21NOAA 1991–2020 normals, Iowa City Municipal Airport (1.3 mi, 50% dates)~3 weeks
- Winter wildlife · Emiquon Refuge · 118 miUsually: migration typically peaks in November~5 weeks
Your guide around Iowa City
Nearby, season by season
Spring migration
- Port Louisa Refuge · 37 miLocal timing: April to May~6 months
Winter wildlife
- Emiquon Refuge · 118 miUsually: migration typically peaks in November~5 weeks
- Chautauqua Refuge · 120 miUsually: Migration typically peaks in November~5 weeks
- Meredosia Refuge · 135 miUsually: migration typically peaks in November~5 weeks
Iowa City's nature year
- Spring migration · Port Louisa RefugeApr–May
- Apr: Spring green-upApr
- Apr: Last spring frostApr
- Oct: First fall frostOct
- Nov: Winter wildlife · Emiquon RefugeNov
Iowa City's year at a glance
- Frost possible
- Frost-free, ~Apr 21 to ~Oct 18
- First leaf ~Apr 5
- First bloom ~May 2
- Today
Frost and green-up
Last spring frost
Apr 21
Average (50% date)
First fall frost
Oct 18
About 180 days without frost between
Spring green-up
Apr 5
First bloom around May 2
Frost: NOAA 1991–2020 climate normals at Iowa City Municipal Airport (1.3 mi from Iowa City), the day a 32 °F night is as likely as not. Green-up: the USA-NPN Spring Index, 1991–2020 average at the town.
Snow in Iowa City
Snow usually becomes possible around Dec 10 (our calculation from NOAA's daily snow chances: the first day the chance of 0.1" or more of snow reaches 10%). NOAA's normals at Iowa City (3.5 mi away): 28 inches of snow in an average year, about 10.4 days with 1 inch or more.
NOAA's chance of at least 0.1 inch of snow on each date (one value per week, September to May), averaged over 1991–2020. A typical year, not a forecast.
Questions people ask
When is the first frost in Iowa City?
On average around Oct 18, and the last spring frost around Apr 21: about 180 days without frost between. These are NOAA's 1991–2020 normals at Iowa City Municipal Airport, 1.3 miles away (the day a 32 °F night is as likely as not).
When does spring green-up reach Iowa City?
The USA-NPN Spring Index puts first leaf around Apr 5 and first bloom around May 2, on average for 1991–2020 at the town.
Where can I see spring migration near Iowa City?
Port Louisa Refuge, 37 miles (local timing: April to May). Distances are straight-line.
Where can I see winter wildlife near Iowa City?
Emiquon Refuge, 118 miles (usually: migration typically peaks in November); Chautauqua Refuge, 120 miles (usually: Migration typically peaks in November); Meredosia Refuge, 135 miles (usually: migration typically peaks in November). Distances are straight-line.
When does it start snowing in Iowa City?
Snow usually becomes possible around Dec 10: our calculation from NOAA's daily snow chances: the first day the chance of 0.1" or more of snow reaches 10%, at Iowa City. An average year brings 28 inches (NOAA 1991–2020). A typical year, not a forecast.Sources: NOAA NCEI U.S. Climate Normals 1991–2020 (annual/seasonal snowfall) ↗ (opens in a new tab), NOAA NCEI U.S. Climate Normals 1991–2020 (daily snowfall probabilities) ↗ (opens in a new tab)
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)