Checking current alerts… View NWS forecast and alerts.
Will it freeze in San Juan in the next 7 nights?
No overnight lows at or below 32°F are forecast in San Juan during the next 7 nights in the available NWS frost forecast.
Tonight: forecast low 72°F. Above 36°F.
NWS forecast period: Thu, Nov 5, 6:00 PM CST to Fri, Nov 6, 6:00 AM CST.
No nights at or below 36°F in the National Weather Service forecast for the next 7 nights.
- Tonight 72°F Above 36°F · Showers And Thunderstorms Likely
- Fri, Nov 6 67°F Above 36°F · Chance Rain Showers
- Sat, Nov 7 66°F Above 36°F · Showers And Thunderstorms
- Sun, Nov 8 59°F Above 36°F · Chance Rain Showers
- Mon, Nov 9 59°F Above 36°F · Slight Chance Rain Showers
- Tue, Nov 10 62°F Above 36°F · Mostly Cloudy
- Wed, Nov 11 64°F Above 36°F · Mostly Cloudy
Overnight lows from the National Weather Service forecast for this location. This covers the available forecast window, not the first freeze of the whole season. Frost can form above 32°F on clear, calm nights.
Frost and freeze probabilities
Freeze dates shift from year to year. Spring percentages describe the chance of a freeze after the stated date; fall percentages describe the chance of a freeze by that date. The 10% spring date is the cautious one: a later freeze happens about 1 year in 10.
These dates describe historical probabilities, not this year’s forecast or the earliest and latest possible freezes. Different weather stations or probability thresholds can produce different published dates for the same city.
Average first hard freeze in San Juan
Most years have no 28°F hard freeze at Mcallen, according to NOAA’s 1991–2020 Climate Normals. Check the short-term forecast above during cold snaps.
| Temperature | Last spring date 90% · 50% · 10% chance of a later freeze | First fall date 10% · 50% · 90% chance of an earlier freeze | Season |
|---|---|---|---|
| 36°F frost possible | Dec 20 · Jan 27 · Mar 1 | Nov 27 · Dec 19 · Jan 26 | 330 days |
| 32°F freeze | Dec 14 · Jan 9 · Feb 12 | Dec 8 · Jan 1 · Feb 4 | 365 days |
| 28°F hard freeze | Dec 15 · Jan 4 · Feb 9 | Dec 14 · Jan 2 · Feb 6 | 365 days |
Average high temperature by month
1991–2020 normals at Mcallen
Average low temperature by month
Months with lows near or below freezing carry frost risk
Where these frost dates come from
The frost dates for San Juan, TX come from the nearest weather station with freeze statistics in NOAA’s 1991–2020 Climate Normals: Mcallen (station USC00415701, elevation 100 ft), 6.2 mi from San Juan. Local conditions (valleys, hilltops, distance to water, city heat) can shift frost dates by days or weeks. The hardiness zone is from the 2023 USDA Plant Hardiness Zone Map (USDA ARS and Oregon State University PRISM). See our methodology.
Frost dates near San Juan
| City | Distance | Last spring frost | First fall frost |
|---|---|---|---|
| Alamo, TX | 2.5 mi | rare | rare |
| Pharr, TX | 3.1 mi | rare | rare |
| McAllen, TX | 6.2 mi | rare | rare |
| Donna, TX | 7.5 mi | rare | rare |
| Hidalgo, TX | 8.1 mi | rare | rare |
| Edinburg, TX | 8.7 mi | rare | rare |
| Weslaco, TX | 11 mi | rare | rare |
| Mission, TX | 11 mi | rare | rare |
| Alton, TX | 12 mi | Jan 23 | Dec 28 |
| Elsa, TX | 12 mi | Jan 10 | Dec 27 |
Frequently asked questions
When is the last frost in San Juan?
San Juan doesn’t reach 32°F in a typical year, according to NOAA’s 1991–2020 normals for the nearest station.
When is the first frost in San Juan?
Freezes are uncommon here; check the 7-night forecast above during cold snaps.
Can it frost in San Juan after the last frost date?
Yes. Frost can form on clear, calm nights even when the air stays above 32°F. Temperatures of 36°F or lower, cold enough for frost on exposed plants, have a 50% chance of occurring after January 27.
What growing zone is San Juan?
San Juan is in USDA Plant Hardiness Zone 10a (average annual extreme minimum temperature 30 to 35°F), based on the 2023 USDA map for ZIP code 78589. See growing zones in Texas.
More: all Texas frost dates · Texas growing zones · UV index today in San Juan · frost vs. freeze