Past 12 months · daily temperature and running heat-wave / cold-snap length
Each of the last 12 months, ranked against the same month in all years
Each month's hottest and coldest day are ranked against the same calendar month across the whole record (Julys against Julys), so seasonality doesn't skew the comparison. Months need at least 25 days of valid data to be ranked; the current in-progress month shows as “—”. Highlighted rows rank in that month's all-time top 10 on either measure.
Hottest and coldest months on record
Ranked by mean temperature (the average of each day's own mean, over the whole month) — the standard measure of how hot or cold a month was overall, since a single scorching afternoon or cold snap doesn't necessarily make the month itself remarkable. Daily max/min extremes are covered separately above; this is about the month as a whole.
Hottest months
Coldest months
Each of the last 12 months' mean temperature, ranked against the same month in all years
Mean temperature per month, ranked against the same calendar month across the whole record (Julys against Julys) both ways — warmest rank and coldest rank always sum to n+1, so a month low on one is necessarily high on the other. Months need at least 25 days of valid data; the current in-progress month shows as “—”. Highlighted rows rank in that month's all-time top 10 on either measure.
Hottest and coldest stretch of each year
Longest heat wave / cold snap of each year
All-time top 10 stretches
Hottest
Coldest
All-time top 10 heat waves / cold snaps
Longest heat waves
Longest cold snaps
Top 10 · last 25 years
Hottest stretches
Coldest stretches
Longest heat waves
Longest cold snaps
A "hot day" has a max temp above this station's own climatological mean+1σ for that calendar day (±7-day window, pooled across the whole record); a "cold day" has a min temp below mean−1σ. Heat waves and cold snaps are runs of consecutive hot/cold days — a missing or invalid day always ends a run, so record gaps can shorten a streak but never fabricate one. "Hottest/coldest stretch" events use the raw max/min temp average over the selected window and are non-overlapping, like the extreme-precipitation page. Annual charts include only years with at least 300 days of valid data for the relevant variable; spells are credited to the year they end in.