Harman US

Frost Dates for Flintstone, MD

Last spring frost
Apr 15
First fall frost
Oct 24
Growing season
190 days
Hardiness zone
7a

In an average year around Flintstone, MD, the last spring frost (32°F) is about Apr 15 and the first fall frost is about Oct 24, giving roughly a 190-day growing season. To be safe most years, wait until Apr 2 before setting out tender plants.

Last spring frost

Dates the last frost of spring typically ends. Plant tender crops after the risk has passed for your comfort level.

Last spring frost - Flintstone, MD
Frost intensity Early (10%) Average (50%) Late (90%)
Light (36°F) May 18 Apr 29 Apr 13
Freeze (32°F) May 5 Apr 15 Apr 2
Hard (28°F) Apr 17 Apr 3 Mar 20
Severe (24°F) Apr 5 Mar 23 Mar 7
Show full probability table (all thresholds & percentiles)
°F 10% 20% 30% 40% 50% 60% 70% 80% 90%
36°F May 18 May 11 May 7 May 2 Apr 29 Apr 25 Apr 21 Apr 18 Apr 13
32°F May 5 Apr 28 Apr 22 Apr 18 Apr 15 Apr 12 Apr 9 Apr 6 Apr 2
28°F Apr 17 Apr 11 Apr 8 Apr 5 Apr 3 Apr 1 Mar 30 Mar 26 Mar 20
24°F Apr 5 Apr 2 Mar 30 Mar 26 Mar 23 Mar 19 Mar 17 Mar 13 Mar 7
20°F Mar 25 Mar 21 Mar 17 Mar 14 Mar 11 Mar 8 Mar 4 Feb 28 Feb 22
16°F Mar 17 Mar 11 Mar 7 Mar 3 Feb 28 Feb 25 Feb 19 Feb 14 Feb 7

First fall frost

Dates the first frost of fall typically arrives. Count back by a crop's days-to-maturity to know your planting cutoff.

First fall frost - Flintstone, MD
Frost intensity Early (10%) Average (50%) Late (90%)
Light (36°F) Oct 1 Oct 13 Oct 26
Freeze (32°F) Oct 9 Oct 24 Nov 6
Hard (28°F) Oct 20 Nov 3 Nov 19
Severe (24°F) Nov 1 Nov 15 Dec 4
Show full probability table (all thresholds & percentiles)
°F 10% 20% 30% 40% 50% 60% 70% 80% 90%
36°F Oct 1 Oct 5 Oct 8 Oct 10 Oct 13 Oct 15 Oct 18 Oct 22 Oct 26
32°F Oct 9 Oct 14 Oct 18 Oct 21 Oct 24 Oct 27 Oct 30 Nov 2 Nov 6
28°F Oct 20 Oct 25 Oct 28 Nov 1 Nov 3 Nov 5 Nov 9 Nov 12 Nov 19
24°F Nov 1 Nov 5 Nov 9 Nov 12 Nov 15 Nov 18 Nov 22 Nov 28 Dec 4
20°F Nov 11 Nov 17 Nov 22 Nov 27 Dec 1 Dec 5 Dec 9 Dec 15 Dec 22
16°F Nov 27 Dec 4 Dec 9 Dec 14 Dec 19 Dec 23 Dec 26 Jan 1 Jan 8

Growing season is measured at 32°F with about 50% probability. Hardiness zone from the 2023 USDA map; frost normals from NOAA 1991-2020.

Where this data comes from

These dates are computed from the nearest official weather station with long-term records: Cumberland 2, Md, about 11.5 miles away@if(!empty($station['elevation_ft'])), at 730 ft elevation. The further the station and the greater the elevation difference from your yard, the more your local frost timing can vary.

@endif
How we calculate these dates

Frost and freeze dates come from the NOAA 1991–2020 U.S. Climate Normals, the National Oceanic and Atmospheric Administration's 30-year averages for each weather station. A date shown at the 50% level is the median: in half of years the frost falls on or before it. The 10% and 90% columns show the early and late ends of the range, so you can plant on the odds you're comfortable with. These are long-term averages, not a forecast for this year - always check your local outlook before planting.

Source: NOAA National Centers for Environmental Information, 1991–2020 Climate Normals (public domain). Harman is not affiliated with or endorsed by NOAA.

Frequently asked questions

When is the last frost in Flintstone, MD?

On average, the last spring frost (32°F) around Flintstone, MD is about Apr 15. In cooler years it can run later, so for a safer bet many gardeners wait until Apr 2.

When is the first frost in the fall?

The first fall frost around Flintstone, MD typically arrives about Oct 24. Count back by a crop's days to maturity to find the latest date you can plant it.

When can I plant tomatoes and other tender crops?

Tender crops like tomatoes, peppers and basil are damaged by frost, so wait until the last spring frost has passed - around Apr 15 on average, or Apr 2 to be safe most years.

How long is the growing season here?

The frost-free growing season (between the last spring and first fall 32°F frost) is about 190 days in a typical year.

Are these dates a forecast for this year?

No. They are 30-year averages from the NOAA 1991–2020 Climate Normals, not a prediction for the current year. Use them for planning and always check your local weather forecast before planting or protecting crops.

Local weather for 21530 Planting calendar → Maryland frost dates →

Data source: NOAA 1991–2020 Climate Normals · Page updated Aug 4, 2026