When to plant pumpkin in Philadelphia

In Philadelphia, typical last spring frost is April 3 and typical first fall frost is November 12. Typical last spring frost: April 3. Pumpkin in Philadelphia is a good fit outdoors. The suitable growing window of 124 days covers the 90–120 days this plant usually needs.

Pumpkin

How to grow Pumpkin Philadelphia climate Weekly temperatures and windows

Where are you growing?

Comfortable

Tight fit in greenhouse

Comfortable in a cold frame

Pumpkin in Philadelphia is a good fit outdoors. The suitable growing window of 124 days covers the 90–120 days this plant usually needs.

When to plantMay 16 – June 19

Harvest: August 14 – November 5
Season vs crop: 124 grow days vs 90–120 needed
Typical frost (last spring – first fall): April 3 – November 12

Pumpkin in Philadelphia is a good fit outdoors. The suitable growing window of 124 days covers the 90–120 days this plant usually needs.

Planting conditions

Direct sow
Grow outdoors
Harvest

Local activity windows for this place and growing method. Blue fill is usually too cold for this plant. Dashed lines are typical last and first frost.

Suitable growing days in a row124

Days to harvest90–120 days from seed

May 16 – Jun 19

Direct sow

Jun 20 – Aug 13

Grow outdoors

Aug 14 – Nov 5

Harvest

Activity	Window	Notes
Direct sow	May 16 – Jun 19	Plant outdoors in this window.
Grow outdoors	Jun 20 – Aug 13	Plants grow outdoors until harvest.
Harvest	Aug 14 – Nov 5	Expected harvest from typical days to harvest.

Direct sow
Grow outdoors
Harvest

Blue fill is usually too cold for this plant. Dashed lines are typical last and first frost (35 seasons (1991–2025)). Adjust a week or two for your conditions.

Planting and growing across the year

Planting is the sow / plant-out window. Growing is daytime air versus this plant’s ideal (21 – 35 °C70 – 95 °F21 – 35 °C (70 – 95 °F)) and tolerable (16 – 38 °C61 – 100 °F16 – 38 °C (61 – 100 °F)) ranges.

Ideal / plantable
Tolerable
Too cold
Too hot
Outside window

Planting uses sow / plant-out rules; growing shows daytime air against this plant’s ideal and tolerable ranges.

Key dates

Typical last spring frostApril 3

Low-risk last spring frostApril 13

Typical first fall frostNovember 12

Low-risk first fall frostNovember 5

Frost-free days222

Outdoor sow dateMay 16

Direct sow windowMay 16 – June 19

Suitable growing windowMay 16 – September 16 (124 days)

Expected harvestAugust 14 – November 5

How these dates are judged

Ideal conditions: Daytime air from 21 – 35 °C70 – 95 °F21 – 35 °C (70 – 95 °F).
Suitable conditions: Daytime air from 16 – 38 °C61 – 100 °F16 – 38 °C (61 – 100 °F).
Last frost and first frost: Typical spring and fall frost dates for Philadelphia, shown in the key dates.
Days to harvest: 90–120 days from seed, from typical days to harvest.
Sowing window: Dated sow and harvest bars use frost dates, soil minima, night limits, and last-sow count-back from typical crop timing. Air ratings on the weekly chart colour only weeks inside that same window — see weekly temperatures and windows.

Other plants for Philadelphia

Calculated by Plan & Plant. Method. Data 35 seasons (1991–2025).

Frost and suitability dates are typical figures from climate statistics.

Based on 35 years (1991–2025) of ERA5-Land data from Open-Meteo, for an area of about 10 km. Typical dates, not a guarantee.

Dates for Philadelphia use ERA5-Land cell 39.95, -75.16. How we calculated this · Algorithm 2026-10-season-10.

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