London frost dates and planting season

Name: London
Address: England, United Kingdom

When to plant vegetables here. Cover calendars (fleece, cold frame, unheated greenhouse) are on each plant’s when-to-plant page.

London has a long growing season, with roughly 255 frost-free days between the typical frost dates. Typical last spring frost: around April 1 (half of years later). Typical first fall frost: around December 13. Plant cool-season crops after about March 9; wait until about June 1 for warm-season crops.

Frost-free days255Apr 1 – Dec 13

Frost-free season in London. Based on average frost dates. Adjust a week or two for your conditions.

Cover calendars (fleece, cold frame, unheated greenhouse) live on each crop’s when-to-plant page.

Weekly possible temperature−7 – 36 °C

Frost-free days255

Typical last spring frostApril 1

Typical first fall frostDecember 13

Days suitable for warm-season vegetables126 (June 1 – October 4)

Days suitable for cool-season vegetables277 (March 9 – November 22)

Calculated by Plan & Plant · Method · Data 2019–2026

Frost and suitability dates are typical figures from climate statistics. Microclimates vary; they are not a guarantee.

Frost dates calculated by Plan & Plant from Weather data by Open-Meteo.com (CC BY 4.0). Local frost pockets, valleys and coastal sites can differ by 1–3 weeks.

How we calculated this

Data: ERA5-Land via Open-Meteo, cell 51.50, -0.10, years 2019–2026 (not a 30-year climate normal yet).
Typical and safer dates: Typical last frost is the date after which half of winters in this sample had no more frost; safer is later in the sample so fewer winters still frosted.
Confidence: Provisional — short or thin sample for this place.
Full methodology (algorithm 2026-10-season-6).

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What to plant when

Cool-season vegetables

Earliest outdoor start: March 9

Suitable window: March 9 – November 22

Cool-season crops prefer cooler weather.

See cool-season details

Warm-season vegetables

Earliest outdoor start: June 1

Suitable window: June 1 – October 4

Warm-season crops need mild or warm weather and cannot take frost.

Frost kills these crops, and cold snaps set them back.

See warm-season details

Green = usually good weeks to grow; blue or gray = usually too cold for that crop type.

Starter plants for London

Cool-season

Radish Sow: February 18 – November 8 Planting dates
Arugula Sow: February 18 – October 26 Planting dates
Spinach Sow: February 18 – October 19 Planting dates
Lettuce Sow: February 18 – October 14 Planting dates
Kale Sow: February 18 – April 14 Planting dates
Beet Sow: March 4 – September 14 Planting dates

Warm-season

Zucchini Sow: June 16 – August 10 Planting dates
Cucumber Sow: June 16 – August 10 Planting dates
Green bean Sow: May 17 – September 5 Planting dates
Tomato Transplant: May 30 – July 24 Start indoors, then transplant. Planting dates
Bell pepper Transplant: June 16 – August 2 Start indoors, then transplant. Planting dates

How these dates are judged

Last frost: The typical last spring date when frost is still expected.
First frost: The typical first fall date when frost returns.
Frost-free days: The approximate days between those two dates.
Cool-season vegetables: Crops that prefer cooler weather, such as lettuce, kale, peas, and radish.
Warm-season vegetables: Crops that need warm weather and cannot take frost, such as tomato, pepper, squash, and beans.

Cool-season planting window

Mar 9 – Nov 22; Dec 14 – Dec 31 (277 days)

Warm-season planting window

Jun 1 – Oct 4 (126 days)

Usually too cold

January 1 – February 15
February 23 – March 8
November 23 – December 13

Weekly temperatures and planting windows

Temperatures across the year for London, with cool- and warm-season weeks and frost dates.

Possible min to max
Average min to max
Suitable
Tolerable
Too cold
Too hot

Selected week · tap a week or use the arrows

Week 11 · Mar 9 – Mar 15

Average 5 to 11 °C · Possible −3 to 15 °C

Cool season: tolerable

Warm season: too cold

A week is suitable for a crop type when its average low and high sit inside that type's range and its possible readings stay within the frost and heat limits (cool: −2 °C to 27 °C, warm: 0 °C to 32 °C); crossing a limit makes it tolerable, and for warm crops any chance of frost makes it too cold.

Based on average frost dates.

England, United Kingdom · 51.5, -0.09999 · 2026

Coldest weekly possible temperature−7 °C

Hottest weekly possible temperature36 °C

Last expected spring frostApril 1

First expected fall frostDecember 13

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