Frost dates for Hopkinton Lake, New Hampshire
Half of years have their last spring frost by May 6, but 1 year in 10 still frosts after May 20.
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
- May 20
- 1 year in 5
- May 16
- 3 years in 10
- May 12
- 2 years in 5
- May 9
- Half of years (the median)
- May 6
First fall freeze
How often the first freeze comes on or before each date.
- 1 year in 10
- September 20
- 1 year in 5
- September 24
- 3 years in 10
- September 28
- 2 years in 5
- September 30
- Half of years (the median)
- October 1
- Growing season
- about 146 days
- Hardiness zones nearby
- 5b, 6a
- Summer days
- a usual high of about 27 °C80 °F
- Lettuce and spinach run to seed
- June to August, 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 ~0 °C32 °F · low ~-11 °C13 °F · rain ~84 mm3.3 in
- February
- high ~2 °C36 °F · low ~-12 °C11 °F · rain ~78 mm3.1 in
- March
- high ~6 °C43 °F · low ~-7 °C20 °F · rain ~95 mm3.7 in
- April
- high ~14 °C57 °F · low ~0 °C32 °F · rain ~98 mm3.9 in
- May
- high ~20 °C69 °F · low ~6 °C43 °F · rain ~93 mm3.7 in
- June
- high ~25 °C77 °F · low ~11 °C52 °F · rain ~114 mm4.5 in
- July
- high ~28 °C83 °F · low ~14 °C58 °F · rain ~109 mm4.3 in
- August
- high ~27 °C81 °F · low ~13 °C56 °F · rain ~102 mm4 in
- September
- high ~23 °C74 °F · low ~8 °C47 °F · rain ~102 mm4 in
- October
- high ~16 °C60 °F · low ~3 °C37 °F · rain ~138 mm5.4 in
- November
- high ~9 °C47 °F · low ~-2 °C28 °F · rain ~98 mm3.9 in
- December
- high ~3 °C37 °F · low ~-7 °C19 °F · rain ~110 mm4.3 in
Where these numbers come from
NOAA NCEI 1991–2020 Climate Normals, the Hopkinton Lake station (listed by NOAA as Hopkinton Lake, USC00274218), at 43.19, -71.75. 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
03043, 03229, 03242, 03244, 03281, 03440, 03442.
Nearby stations
The nearest stations and how their last-frost dates compare. Together they show how frost varies across your area.
- Newport, NH, last frost by May 14
- Greenville 1 NNE, NH, last frost by May 10
- Epping, NH, last frost by May 7
- Lawrence, MA, last frost by April 13
- Tully Lake, MA, last frost by April 25
- E Sandwich, NH, last frost by May 6
When do I plant? · Where the dates come from
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