Nagasaki, Japan · population 97,371 · 50 weather stations within 200 km · records 1819 to 2025
Isahaya has an average annual daytime high of 19.3°C, based on the 1951 to 1980 baseline. Its warmest month is August, when highs typically reach 30.2°C, and its coldest is January, with overnight lows near 1.3°C.
These figures reflect annual averages, not single-day records. Daily observations are outside this dataset's precision.
Since 1900, Isahaya's average temperature has risen by +2.4°C. Compared to the earliest station records that begin in 1819, warming totals +2.2°C.
20-year smoothed annual temperature reconstructed from station anomalies. Dashed line: 1951–1980 baseline.
Daytime highs sit within a comfortable 15°C to 26°C range.
Isahaya's average annual daytime high is 19.3°C, based on the 1951 to 1980 baseline period. The warmest month is August, with highs averaging 30.2°C, and the coldest is January, with lows averaging 1.3°C.
August is the warmest month in Isahaya, with typical daytime highs of 30.2°C.
2023 is the hottest year on record for Isahaya, running +1.8°C above the 1951 to 1980 baseline.
Yes. Since 1900, Isahaya has warmed by roughly +2.4°C.
April to November typically offers the most comfortable daytime highs, in the 15°C to 26°C range.
Baseline period 1951 to 1980. Monthly averages are the mean of station observations weighted by proximity. Warming trend is the 20-year smoothed anomaly against that baseline.