Phoenix Sky Harbor INTL AP
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.
Infrequent freezing; conditional datesOne 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The 10% date is later in spring than the median: a more cautious historical reference, still not a guarantee.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.
The reference
behind the numbers.
- Official station name
- PHOENIX SKY HARBOR INTL AP, AZ US
- NOAA station ID
- USW00023183
- Coordinates
- 33.4278, -112.0039
- Station elevation
- 337.4 m / 1107 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% | Jan 22 | 29 | S · Standard |
| Last spring freeze · 30% | Jan 9 | 29 | S · Standard |
| Last spring freeze · 50% | Jan 5 | 29 | S · Standard |
| First fall freeze · 10% | Dec 18 | 29 | S · Standard |
| First fall freeze · 30% | Dec 30 | 29 | S · Standard |
| First fall freeze · 50% | Jan 3 (next year) | 29 | 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.