How extreme does Grantham's weather get?

The hottest, coldest, wettest and snowiest days Grantham has recorded — the outer limits of what its weather can do, and how far they sit beyond a normal day.

Based on 23 years of daily weather observations (2002–present), from the Barkston Heath station 8 km away. Updated through August 2025 — an all-time extreme only changes when a more extreme day actually occurs, so some dates are old. That is normal, not stale data.

The four kinds of extreme

The hottest, coldest, wettest and snowiest single days Grantham has recorded — each shown against what a normal day that time of year looks like.

🔥 Hottest day

88°F Sep 9, 2023

The three most extreme on record

1 88°F Sep 9, 2023recent

2 88°F Jun 30, 2025

3 88°F Jul 11, 2025

❄️ Coldest night

21°F Jan 17, 2024

The three most extreme on record

1 21°F Jan 17, 2024recent

2 21°F Jan 18, 2024

3 23°F Jan 9, 2025

In plain terms

Across the record, Grantham has reached as high as 88°F and as low as 21°F. Those are the outer edges worth knowing if you are moving here, planning a trip, or thinking about a house.

Methodology & sources

Temperature & precipitation — 1991–2020 normals computed from 30 years of daily observations at Cranwell, a weather station, about 17 km from the city centre. The underlying daily records come from NOAA's global station network.

How we build these numbers →

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