When to plant in Harlingen, TX
USDA Zone 10aHarlingen, Texas frost dates, USDA zone, and a full-year planting calendar, drawn from the nearest NOAA station and tuned to the local season.
With only about -6 frost-free days, Harlingen has a short season — start heat-lovers indoors early, favor quick-maturing varieties, and use row cover to stretch both ends. Zone 10a is warm enough that Harlingen can grow subtropical perennials, and the short (or absent) frost period barely limits the annual calendar.
Frost probability
HARLINGEN · 1991–2020The date the last spring and first fall frost occur, by threshold and probability. A 90% date is later in spring — and earlier in fall — than a 10% date; the 50% · 32°F row is what most gardeners plan around. These are Harlingen’s own odds, recorded at HARLINGEN.
| Threshold | SPRING 10% | SPRING 50% | SPRING 90% | FALL 10% | FALL 50% | FALL 90% |
|---|---|---|---|---|---|---|
| 36°F | Feb 28 | Jan 21 | Dec 17 | Nov 29 | Dec 26 | Feb 2 |
| 32°F | Feb 4 | Jan 9 | Dec 15 | Dec 9 | Jan 3 | Jan 29 |
Download this table as CSV ↓ — every threshold and probability, plus this city’s planting-window dates.
What to plant now
TODAY · JULY 19Nothing new to sow or transplant outdoors in the next few weeks — a seasonal lull. Check the full-year calendar below for the next window.
Full-year planting calendar
Each bar is the exact window to take a planting action in Harlingen, drawn to the day from the local frost dates. The dashed line is today.
Nearby weather stations
3 within 19 km · complete 32°F normalsWhen stations disagree by more than a few days, that spread is real microclimate variation — elevation, water, urban heat. Judge which station best matches your own yard.
Harlingen planting FAQ
When is the last spring frost in Harlingen, TX?
Plan for the last spring frost in Harlingen around January 9 (the date it has a 50% chance of a 32°F freeze). Anything frost-sensitive should go out after it.
When is the first fall frost in Harlingen, TX?
In Harlingen, the first 32°F freeze of fall lands around January 3 on average. Time your last harvests and any season-extension cover before it.
What hardiness zone is Harlingen in?
Harlingen is in USDA hardiness zone 10a. In zone 10a, winters are mild — many tender perennials overwinter here.
How long is the growing season in Harlingen?
There are roughly -6 frost-free days in Harlingen (a short growing season), running from the average last frost around January 9 to the first fall frost near January 3.
When should I plant tomatoes in Harlingen?
In Harlingen, start tomato seeds indoors around November 14–November 28, then transplant seedlings outdoors around January 16 once the danger of frost has passed.
Never miss a window in Harlingen
An email when it’s time to start seeds, transplant, and sow — timed to Harlingen’s frost dates. Double opt-in, one-click unsubscribe, no spam.
Nearby cities
8 within reach- San Benito · 9 km
- Mercedes · 22 km
- Weslaco · 29 km
- Brownsville · 31 km
- Raymondville · 33 km
- Donna · 34 km
- Alamo · 42 km
- San Juan · 45 km
Frost dates recorded at HARLINGEN, 3 km from the city center · 1991–2020 NOAA climate normals · zone from the USDA/PRISM 2023 map. How we compute this.
BlissGarden. "When to Plant in Harlingen, TX — Frost Dates & Zone 10a." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USC00413943. Retrieved from https://blissgarden.com/texas/harlingen.