How extreme does Borgarnes's weather get?

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

Based on 6 years of daily weather observations (2019–present), from the Stafholtsey station 18 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 Borgarnes has recorded — each shown against what a normal day that time of year looks like.

🔥 Hottest day

77°F May 18, 2025

The three most extreme on record

1 77°F May 18, 2025recent

2 77°F Jul 14, 2025

3 75°F Jul 9, 2023

❄️ Coldest night

-9°F Dec 30, 2022

The three most extreme on record

1 -9°F Dec 30, 2022recent

2 -7°F Dec 29, 2023

3 -7°F Dec 22, 2023

In plain terms

Across the record, Borgarnes has reached as high as 77°F and as low as −9°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 11 years of daily observations at Keflavik, a weather station, about 72 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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