The most hot days Lyon has recorded by this date.

Lyon is compared against 1991-2020, not 1961-1990. This thermometer starts in 1975, so the earlier window every other city uses would cover only its warmer final years here, and a figure against that would look like every other city's while meaning something weaker. 1991-2020 is complete for this station, so it is the one shown. The count and the rank are measured on the full record and stand.

Hot here means 34.7 °C or above, a level about one summer day in twenty used to reach at this station between 1991 and 2020. The percentile thresholds on this page are computed over this period. Where it is not the default 1971-2000, the city's record does not cover that window and a complete later WMO normal is used instead, which yields a HIGHER threshold and so understates rather than overstates. The bar has not moved; the number of days clearing it has. Every year is counted to 8 August, so a part-finished summer is never set against complete ones. That threshold is Lyon's own. It is not a national standard and it is not comparable with another city's: every figure on this page is measured against this station and nothing else.

34 nights so far that never dropped below 20 °C. That is 1st of its 52 summers.

Lyon's hottest day this year, 38.1 °C, is 7th on this record. The previous best is 39.4 °C in 2019, the dot on the drop line. A typical summer here peaks at 34.8 °C. Its hot-day count is the most on record by this date: a count and a peak are different claims, and neither borrows the other's rank.

42 cities are measured this way, each against its own record. See them on the map