When to plant in Rio Grande City, TX
USDA Zone 9bRio Grande City, Texas frost dates, USDA zone, and a full-year planting calendar, drawn from the nearest NOAA station and tuned to the local season.
Rio Grande City enjoys a long ~320-day frost-free season — you can succession-sow, fit in a second crop, and grow long-season heat-lovers with room to spare. Zone 9b is warm enough that Rio Grande City can grow subtropical perennials, and the short (or absent) frost period barely limits the annual calendar.
Frost probability
RIO GRANDE CITY · 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 Rio Grande City’s own odds, recorded at RIO GRANDE CITY.
| Threshold | SPRING 10% | SPRING 50% | SPRING 90% | FALL 10% | FALL 50% | FALL 90% |
|---|---|---|---|---|---|---|
| 36°F | Mar 14 | Feb 22 | Jan 22 | Nov 11 | Dec 1 | Dec 28 |
| 32°F | Mar 4 | Jan 31 | Dec 29 | Nov 22 | Dec 17 | Jan 20 |
| 28°F | Feb 20 | Jan 12 | Dec 13 | Dec 2 | Dec 29 | Feb 1 |
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 Rio Grande City, drawn to the day from the local frost dates. The dashed line is today.
Nearby weather stations
2 within 37 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.
Rio Grande City planting FAQ
When is the last spring frost in Rio Grande City, TX?
Rio Grande City's average last spring frost falls near January 31 — the 50% mark at 32°F in the 1991–2020 normals. Hold tender transplants until the risk has passed, then plant out.
When is the first fall frost in Rio Grande City, TX?
The first fall frost in Rio Grande City typically arrives around December 17 (50% probability at 32°F). Harvest or protect frost-sensitive crops before then.
What hardiness zone is Rio Grande City in?
Rio Grande City is in USDA hardiness zone 9b. In zone 9b, winters are mild — many tender perennials overwinter here.
How long is the growing season in Rio Grande City?
There are roughly 320 frost-free days in Rio Grande City (a long growing season), running from the average last frost around January 31 to the first fall frost near December 17.
When should I plant tomatoes in Rio Grande City?
In Rio Grande City, start tomato seeds indoors around December 6–December 20, then transplant seedlings outdoors around February 7 once the danger of frost has passed.
Never miss a window in Rio Grande City
An email when it’s time to start seeds, transplant, and sow — timed to Rio Grande City’s frost dates. Double opt-in, one-click unsubscribe, no spam.
Nearby cities
8 within reachFrost dates recorded at RIO GRANDE CITY, 1 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 Rio Grande City, TX — Frost Dates & Zone 9b." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USC00417622. Retrieved from https://blissgarden.com/texas/rio-grande-city.