USDA Hardiness Zone 5b
Frost Dates for 52403 — Cedar Rapids, Iowa
Averages from Cedar Rapids #1, Ia US, the nearest reporting station, 4.9 miles away.
Plant tender crops after April 28, and expect the first autumn freeze around October 12. That leaves about 166 frost-free days.
- Last spring frost
- April 28
- First fall frost
- October 12
- Growing season
- 166 days
- Hardiness zone
- 5b
50% probability
50% probability
frost-free
-15 to -10°F annual low
- First snow
- November 14
- Last snow
- March 31
- Winters with snow
- 100%
- Snow per year
- 34.3"
median, 1991–2020
median, 1991–2020
30 of 30 observed
NOAA normal
When it snows in Cedar Rapids, Iowa
The first measurable snow (0.1 inch or more) in Cedar Rapids, Iowa usually arrives around November 14, and the last of the season around March 31. Those are the middle dates across the winters of 1991–2020 at Cedar Rapids #1, Ia US: half of years saw snow earlier, half later. Every one of those winters saw snow.
For a gardener, snow matters less than frost: a light snow on frozen ground changes nothing, while a hard frost on an unprotected bed ends the season. Use the frost dates above for planting and the snow dates for getting hoses drained, mulch down and tender pots indoors.
Planting calendar for 52403
| When | What to do |
|---|---|
| February 17 – March 3 | Start peppers and aubergines indoors They need eight to ten weeks under lights before they can go out. |
| March 3 – March 17 | Start tomatoes indoors Six to eight weeks gives a transplant big enough to set fruit early. |
| March 31 – April 14 | Sow peas, spinach, lettuce, radish outdoors These tolerate light frost and prefer to germinate in cool soil. |
| April 28 onward | Transplant tomatoes, peppers, basil, squash, cucumbers The average last freeze has passed — still watch the actual forecast. |
| by July 20 | Sow the autumn crop of carrots, beets and brassicas They need about twelve weeks to size up before growth stops. |
| by September 28 | Harvest tender crops, or be ready to cover them A first freeze two weeks early is well within normal variation. |
| October 12 onward | Plant garlic, mulch beds, lift tender bulbs Garlic wants a cold spell; bare soil loses structure over winter. |
What these dates mean
Wait until after April 28 to put tender plants — tomatoes, peppers, basil, squash — in the ground. That is the date by which half of years in Cedar Rapids, Iowa are past their last freeze. Harvest before October 12, which leaves roughly 166 frost-free days.
ZIP 52403 sits in USDA hardiness zone 5b, meaning the average coldest night of the year falls between -15 to -10°F. Zone decides what survives the winter; frost dates decide when to plant each spring. They are different questions, and a plant can pass one and fail the other.
These are thirty-year NOAA averages for 1991–2020, not a forecast. Any individual year can frost two to three weeks either side of these dates, so check the actual forecast before planting out.