Frost dates for Conroe, Texas
In Conroe, half of springs have had their last frost by March 11 (and 1 spring in 10 still has one after April 3), and half of falls have had their first frost by November 19, leaving about 253 frost-free days in a typical year. Here is how sure those dates are, what they mean for planting, and where they come from.
Frost dates for
Conroe, Texas
Last spring frost
March 11
Half of springs have their last frost by this date. For a safer bet, wait until April 3: only 1 spring in 10 has a frost after that.
First fall frost
November 19
Half of falls have their first frost by this date. In 1 fall in 10 it comes by November 1.
Growing season
253 days
Frost-free days in a typical year. 9 years in 10 get at least 224.
Hardiness zone
9a
2023 USDA map: the coldest night of winter averages 20°F to 25°F. On the 2012 map it was 8b, half a zone colder. All 2 ZIP codes within about 6 miles of the city's center are in zone 9a.
Stations near you disagree. NOAA's Conroe Montgomery Co Airport (5 miles away, at 250 feet above sea level), the one we used, gives a typical last frost of March 11 and a typical first frost of November 19. NOAA's Conroe (less than a mile away, at 250 feet above sea level) gives a typical last frost of February 24 and a typical first frost of December 2. So the typical last frost could fall anywhere from February 24 to March 11 and the typical first frost from November 19 to December 2, depending on whether your garden is more like one or the other. Local terrain matters: hillsides, valley floors, water and city heat can change frost dates a lot over a few miles. Treat the dates here as a starting point, and compare with a nearby gardener or your county extension office.
Print a year planner for Conroe
Frost risk through the year
How sure are these dates?
A frost date is a probability, not a promise. NOAA worked out, from 30 years of nightly lows, how often the last spring frost and the first fall frost fall on each date. The middle column is the typical year. The outer columns are the early and late years that come about once a decade.
| Early year 1 in 10 | Typical year 1 in 2 | Late year 1 in 10 | |
|---|---|---|---|
| Last frost in spring | February 14 | March 11 | April 3 |
| First frost in fall | November 1 | November 19 | December 9 |
The frost-free season between them runs 253 days in a typical year. In 1 year in 10 it is 286 days or longer, and in 1 year in 10 it is 224 days or shorter.
- Hard freeze (28°F): typically last on February 21 and first on December 4. It is a harder freeze than the 32°F frost line, cold enough to damage many garden plants; how hardy a crop is decides whether it comes through. (The National Weather Service's own hard-freeze threshold varies from office to office.)
- Frost possible (36°F at the station): typically last on March 24 and first on November 8. On clear, still nights the ground can be several degrees colder than the thermometer, so frost can form on plants when the official reading is in the mid-30s.
In 8 springs out of 10, the last frost in Conroe comes between February 14 and April 3, a window of 48 days. That is wider than at most NOAA stations (the typical window is 31 days), so spring here is less predictable than average: lean toward the later date.
Among Texas's 387 NOAA stations with a frost every year, 68 percent have their typical last frost later than Conroe does.
Planting calendar for Conroe
These dates count from the typical last and first frosts, using the planting rules published by Colorado State University Extension (spring), Virginia Cooperative Extension (fall crops) and University of Minnesota Extension (garlic, where winters are hard). Weather in any one year can run early or late, so check the forecast before you plant tender crops.
We don't give a garlic date here. The rule we use, from the University of Minnesota Extension, counts from the first killing frost, and it works where a hard freeze comes every year before the ground freezes. Your county's extension office can tell you when to plant garlic in your climate.
| When | What to do | Why then |
|---|---|---|
| January | ||
| January 7 to February 4 | Cauliflower Start seeds indoors | 5 to 7 weeks before planting out |
| January 21 to February 11 | Eggplant Start seeds indoors | 6 to 9 weeks before planting out |
| January 28 to February 11 | Peppers Start seeds indoors | 6 to 8 weeks before planting out |
| February | ||
| February 4 to 18 | Tomatoes Start seeds indoors | 5 to 7 weeks before planting out |
| February 11 to 25 | Peas, spinach, lettuce, radishes, onion sets, turnips Sow outdoors, as early as | hardy crops: 2 to 4 weeks before the typical last frost |
| February 11 to 25 | Broccoli and cabbage Plant out, as early as | hardy crops: 2 to 4 weeks before the typical last frost |
| February 25 to March 11 | Beets, carrots, potatoes, Swiss chard Plant outdoors, as early as | semi-hardy crops: up to 2 weeks before the typical last frost |
| February 25 to March 11 | Cauliflower Plant out, as early as | semi-hardy: up to 2 weeks before the typical last frost |
| March | ||
| March 11 | Snap beans, sweet corn, cucumbers, summer squash Sow outdoors around | tender crops: around the typical last frost date |
| March 25 | Tomatoes, peppers, eggplant Plant out from | very tender: 2 weeks or more after the typical last frost |
| March 25 | Melons, winter squash, pumpkins, lima beans Sow outdoors from | very tender: 2 weeks or more after the typical last frost |
| June | ||
| June 24 to July 8 | Cabbage for fall Start seeds | set the plants out by August 12 |
| July | ||
| July 14 to 28 | Broccoli for fall Start seeds | set the plants out by September 1 |
| August | ||
| August 23 | Snap beans for fall Last date to sow | 60 days to harvest, plus 2 weeks for slower fall growth, plus 2 weeks because frost kills it |
| August 27 | Carrots for fall Last date to sow | 70 days to harvest, plus 2 weeks for slower fall growth |
| August 28 | Cucumbers for fall Last date to sow | 55 days to harvest, plus 2 weeks for slower fall growth, plus 2 weeks because frost kills it |
| September | ||
| September 1 | Peas for fall Last date to sow | 65 days to harvest, plus 2 weeks for slower fall growth |
| September 2 | Summer squash for fall Last date to sow | 50 days to harvest, plus 2 weeks for slower fall growth, plus 2 weeks because frost kills it |
| September 6 | Leaf lettuce and beets for fall Last date to sow | 60 days to harvest, plus 2 weeks for slower fall growth |
| September 16 | Turnips and kohlrabi for fall Last date to sow | 50 days to harvest, plus 2 weeks for slower fall growth |
| September 26 | Spinach for fall Last date to sow | 40 days to harvest, plus 2 weeks for slower fall growth |
| October | ||
| October 6 | Radishes for fall Last date to sow | 30 days to harvest, plus 2 weeks for slower fall growth |
| November | ||
| November 1 | Tomatoes, peppers, squash, melons, cucumbers Watch the forecast from | in 1 fall in 10 the first frost comes by this date; pick tender crops before a frost |
| December | ||
| December 24 to January 21 | Broccoli and cabbage Start seeds indoors | 5 to 7 weeks before planting them out |
Want more insurance? Shift every spring date 23 days later. That plans around April 3, the date after which only 1 spring in 10 has a frost.
For spring bulbs such as tulips and daffodils, plant once the soil has cooled to about 50 to 55°F and keep going until a couple of weeks before the ground freezes. Our guide to fall planting explains how to tell.
Where these numbers come from
These dates come from NOAA's weather station Conroe Montgomery Co Airport (station USW00053902), 5 miles from the center of Conroe. It sits at about the same elevation, 250 feet above sea level. NOAA rates this station's record as representative: at least 10 of the 30 years, with the gaps filled from nearby stations.
Our ZIP code lookup matches these 6 ZIP codes to the same station, so they get the same dates: 77301, 77302, 77303, 77306, 77358, 77378. Hardiness zones are worked out separately for each ZIP code.
Nearby places
- Houston, Texas: frost not every year (40 miles away)
- Sugar Land, Texas: frost not every year (50 miles away)
- College Station, Texas: last frost around February 27, first frost around November 30 (50 miles away)
See frost dates across Texas, or look up your own ZIP code for the station nearest you. Want the background? Read what a last frost date really means.