Frost dates for Cedar Rapids Municipal Airport, Iowa
Half of years have their last spring frost by April 27, but 1 year in 10 still frosts after May 11.
A frost date is really a percentile from 30 years of records at a nearby weather station: in about half of years a frost still comes after the median date. Both numbers are below, so you can choose the risk yourself.
The odds
Last spring frost
How often a frost still comes on or after each date.
- 1 year in 10
- May 11
- 1 year in 5
- May 6
- 3 years in 10
- May 3
- 2 years in 5
- April 30
- Half of years (the median)
- April 27
First fall freeze
How often the first freeze comes on or before each date.
- 1 year in 10
- September 25
- 1 year in 5
- October 1
- 3 years in 10
- October 5
- 2 years in 5
- October 8
- Half of years (the median)
- October 11
- Growing season
- about 165 days
- Hardiness zones nearby
- 5a, 5b
- Summer days
- a usual high of about 27 °C81 °F
- Lettuce and spinach run to seed
- June to August, in hot, long days (how we know)
Summer and rain
A growing garden needs about 25 mm1 in of water a week, rain and watering together. Here is what a normal month brings.
Month by month
- January
- high ~-2 °C28 °F · low ~-12 °C11 °F · rain ~24 mm0.9 in
- February
- high ~0 °C33 °F · low ~-9 °C15 °F · rain ~31 mm1.2 in
- March
- high ~8 °C46 °F · low ~-3 °C27 °F · rain ~50 mm2 in
- April
- high ~16 °C60 °F · low ~3 °C38 °F · rain ~90 mm3.6 in
- May
- high ~22 °C71 °F · low ~10 °C49 °F · rain ~108 mm4.2 in
- June
- high ~27 °C80 °F · low ~15 °C60 °F · rain ~141 mm5.6 in
- July
- high ~28 °C83 °F · low ~17 °C63 °F · rain ~112 mm4.4 in
- August
- high ~27 °C81 °F · low ~16 °C60 °F · rain ~103 mm4.1 in
- September
- high ~24 °C75 °F · low ~11 °C52 °F · rain ~86 mm3.4 in
- October
- high ~16 °C62 °F · low ~4 °C40 °F · rain ~74 mm2.9 in
- November
- high ~8 °C46 °F · low ~-2 °C28 °F · rain ~51 mm2 in
- December
- high ~1 °C33 °F · low ~-8 °C17 °F · rain ~40 mm1.6 in
Where these numbers come from
NOAA NCEI 1991–2020 Climate Normals, the Cedar Rapids Municipal Airport station (listed by NOAA as Cedar Rapids Muni Ap, USW00014990), at 41.88, -91.72. These are that station’s own records, unshifted. The further your garden is from it, the less exactly they describe your ground. The planner finds the nearest station to your garden and lowers its confidence with distance, so no number is presented as if it were measured in your garden.
Cold air also pools in low ground on the clear, still nights when frost happens, so a hollow can freeze while a slope a few hundred feet away does not. No table can know that about your garden. A few seasons of your own logged frosts can.
ZIP codes nearest this station
52203, 52206, 52227, 52228, 52233, 52236, 52240, 52241, 52242, 52245, 52246, 52307…
+18 moreShow fewer
52314, 52317, 52318, 52322, 52328, 52333, 52334, 52338, 52340, 52341, 52351, 52354, 52401, 52402, 52403, 52404, 52405, 52411.
Nearby stations
The nearest stations and how their last-frost dates compare. Together they show how frost varies across your area.
- Davenport, IA, last frost by April 23
- Aledo, IL, last frost by April 22
- Clinton #1, IA, last frost by April 22
Other stations in Iowa.
- Des Moines Johnston, IA, last frost by April 19
- Sioux City Gateway Airport, IA, last frost by April 29
When do I plant? · Where the dates come from
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