Carroll
frost dates.
A source-backed view of historical freeze risk at this weather station. Use it to understand the season, not as a promise about your garden or this year’s weather.
Seasonal freeze referenceOne date never tells
the whole season.
1991–2020 station normals
32°F minimum-temperature threshold
Last spring freeze
Among cold seasons with a freeze: probability of the last occurrence on this date or later.
The 10% date is later in spring than the median: a more cautious historical reference, still not a guarantee.
First fall freeze
Among cold seasons with a freeze: probability of the first occurrence on this date or earlier.
The 10% date is earlier in fall than the median: a more cautious harvest-planning reference.
These percentages are conditional on a cold season containing a 32°F freeze; they are not probabilities across all years. They describe historical climate, not this season’s forecast. The spring and fall probability directions are intentionally different. A garden can be warmer or colder than the reference station.
Try a harvest scenario.
If a historical freeze reference fits your crop and regional guidance, you can choose it as a calculator target. This action does not turn the date into a recommended harvest deadline.
Choose a planning year.
Percentiles are conditional on a cold season with a freeze. Some crops tolerate freezing; others need warmth well before it. Check crop and local guidance first.
The reference
behind the numbers.
- Official station name
- CARROLL, IA US
- NOAA station ID
- USC00131233
- Coordinates
- 42.0650, -94.8500
- Station elevation
- 378 m / 1240 ft
- Normal period
- 1991–2020
- Source retrieved
- 2026-10-02
- Source modified
- Tue, 27 Jun 2023 15:16:19 GMT
A baseline.
Not a forecast.
Weather stations measure a particular location. Differences in elevation, exposure, nearby water, terrain and urban heat can change conditions in an individual garden.
- 32°F is the station air-temperature threshold; visible frost on leaves can differ.
- Median dates still leave substantial historical freeze risk.
- Historical normals summarize 1991–2020, not current weather.
- Crop suitability requires regional horticultural guidance, soil warmth, cultivar and day length.
How strong is this reference?
| Source variable | Historical date | Years | NOAA completeness |
|---|---|---|---|
| Last spring freeze · 10% | May 8 | 30 | S · Standard |
| Last spring freeze · 30% | May 2 | 30 | S · Standard |
| Last spring freeze · 50% | Apr 27 | 30 | S · Standard |
| First fall freeze · 10% | Sep 25 | 30 | S · Standard |
| First fall freeze · 30% | Oct 2 | 30 | S · Standard |
| First fall freeze · 50% | Oct 10 | 30 | S · Standard |
Our ordinary calendar model requires supported dates and standard/representative source quality with at least 10 years. This does not erase local uncertainty.
Places using this nearby reference
Connections use straight-line distance from Census internal points or explicitly labeled, reviewed city reference points. Each place page explains its reference.
Carroll, IA
1.3 km to this station
See the matchLidderdale, IA
8.4 km to this station
See the matchWilley, IA
9.9 km to this station
See the matchGlidden, IA
10.2 km to this station
See the matchHalbur, IA
12.1 km to this station
See the matchArcadia, IA
16.1 km to this station
See the matchBreda, IA
16.8 km to this station
See the matchDedham, IA
17.6 km to this station
See the match