Frost dates for Hagerstown Washington County Airport, Maryland
Half of years have their last spring frost by April 7, but 1 year in 10 still frosts after April 21.
A frost date is really a percentile from 30 years of records at a nearby weather station: in about half of years a frost still comes after the median date. Both numbers are below, so you can choose the risk yourself.
The odds
Last spring frost
How often a frost still comes on or after each date.
- 1 year in 10
- April 21
- 1 year in 5
- April 16
- 3 years in 10
- April 12
- 2 years in 5
- April 10
- Half of years (the median)
- April 7
First fall freeze
How often the first freeze comes on or before each date.
- 1 year in 10
- October 22
- 1 year in 5
- October 26
- 3 years in 10
- October 29
- 2 years in 5
- November 1
- Half of years (the median)
- November 4
- Growing season
- about 209 days
- Hardiness zones nearby
- 7a, 7b
- Summer days
- a usual high of about 29 °C85 °F
- Lettuce and spinach run to seed
- June to September, in hot, long days (how we know)
Summer and rain
A growing garden needs about 25 mm1 in of water a week, rain and watering together. Here is what a normal month brings.
Month by month
- January
- high ~5 °C40 °F · low ~-4 °C25 °F · rain ~62 mm2.5 in
- February
- high ~6 °C44 °F · low ~-3 °C27 °F · rain ~50 mm2 in
- March
- high ~12 °C53 °F · low ~1 °C34 °F · rain ~77 mm3 in
- April
- high ~18 °C65 °F · low ~7 °C44 °F · rain ~85 mm3.3 in
- May
- high ~24 °C74 °F · low ~12 °C54 °F · rain ~90 mm3.6 in
- June
- high ~28 °C83 °F · low ~18 °C64 °F · rain ~85 mm3.4 in
- July
- high ~31 °C87 °F · low ~20 °C68 °F · rain ~75 mm2.9 in
- August
- high ~29 °C85 °F · low ~19 °C66 °F · rain ~74 mm2.9 in
- September
- high ~25 °C78 °F · low ~15 °C59 °F · rain ~97 mm3.8 in
- October
- high ~19 °C66 °F · low ~9 °C47 °F · rain ~70 mm2.8 in
- November
- high ~12 °C54 °F · low ~3 °C37 °F · rain ~67 mm2.6 in
- December
- high ~7 °C44 °F · low ~-1 °C30 °F · rain ~72 mm2.8 in
Where these numbers come from
NOAA NCEI 1991–2020 Climate Normals, the Hagerstown Washington County Airport station (listed by NOAA as Hagerstown Washington Co Ap, USW00093706), at 39.71, -77.73. These are that station’s own records, unshifted. The further your garden is from it, the less exactly they describe your ground. The planner finds the nearest station to your garden and lowers its confidence with distance, so no number is presented as if it were measured in your garden.
Cold air also pools in low ground on the clear, still nights when frost happens, so a hollow can freeze while a slope a few hundred feet away does not. No table can know that about your garden. A few seasons of your own logged frosts can.
ZIP codes nearest this station
17212, 17224, 17225, 17236, 17252, 17256, 17263, 17270, 17272, 21711, 21722, 21767.
Nearby stations
The nearest stations and how their last-frost dates compare. Together they show how frost varies across your area.
- Shippensburg, PA, last frost by April 19
- Purcellville, VA, last frost by April 16
- Damascus 3 SSW, MD, last frost by April 14
- Carlisle Wtp, PA, last frost by April 23
- Millers 4 NE, MD, last frost by April 19
- Altoona Blair County Airport, PA, last frost by April 23
Other stations in Maryland.
- Cumberland 2, MD, last frost by April 15
- Cylburn, MD, last frost by April 2
- Dalecarlia Rsvr, MD, last frost by April 9
- Baltimore Wash International Airport, MD, last frost by April 10
- Upper Marlboro 3 NNW, MD, last frost by April 9
- Conowingo Dam, MD, last frost by April 3
- Mechanicsville 5 NE, MD, last frost by April 17
- Royal Oak 2 SSW, MD, last frost by April 1
When do I plant? · Where the dates come from
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