Kotō weather history

21 of the last 24 days were warmer than the historical normal for that date. Average difference: +2.2°C.

Each bar is one day, from morning low to afternoon high. Warm-colored bars are days whose mean ran above normal; cool bars ran below. The dot inside the bar is the daily mean. The shaded band is the typical 10–90% range expected for that date. Normal = the day's mean temperature averaged across every year of record (1940–2026) for that calendar date.

Long-term trend: +0.13°C per decade.

One point per year — the average temperature on this calendar date. The dashed line is the long-term trend; the highlighted dot is today's forecast. Based on ERA5 reanalysis — modelled estimates, not station readings.

August is the warmest month, January the coolest — a yearly swing of 21°C.

Each bar is the average daily low → average daily high for that month. Color shifts cool→warm by month temperature. The dot is the monthly mean. Normal = each month's value averaged across every year of record (1940–2026).

Wettest month: June (~367 mm). Whole year averages ~1881 mm of rain.

Average total millimetres of rainfall in each calendar month, across the full record.

Average daily peak wind at 10 m, by month.

Average daily incoming solar energy in megajoules per square metre — a measured proxy for how sunny the month is.

Numerical reference: average highs/lows, mean rainfall, and absolute records for each month of the year. Normal = each month's value averaged across every year of record (1940–2026).

Annual mean shifted from 1940–1949 to 2016–2025 by +2.1°C.

Each vertical stripe is one year. Color encodes how much that year's annual mean differed from the long-term average. Normal = each year's annual mean compared to the average of all years (1940–2026). cooler ← → warmer

Long-term trend: +0.25°C per decade.

One point per year — the temperature averaged across the whole year. The dashed line is the least-squares long-term trend. Based on ERA5 reanalysis — modelled estimates, not station readings.

Autumn is warming fastest: +0.28°C per decade.

Each faint line is one season's average per year; the bold dashed line is that season's long-term trend. Seasons often warm at different rates. Based on ERA5 reanalysis — modelled estimates, not station readings.

Days ≥ 30°C per year: 7.7 early in the record → 44.1 recently. Frost days: 20 → 7.

Thin lines are raw yearly counts; thick lines are the smoothed trend that removes year-to-year noise. The hot-day threshold is auto-picked per city so the line actually moves. Normal = a centered 5-year rolling average to smooth weather noise.

All-time high in 2025, all-time low in 1977: 35.0°C / -10.6°C.

One point per year — the single hottest and coldest day recorded that year.

~1881 mm/year on average. Last decade ran +7% vs that average.

One bar per year of total rainfall. Dashed line is the long-term average. Normal = the average annual rainfall across every year of record (1940–2026).

Each tiny square is one calendar day across the full record — ~30,000 days per city. Use the mode switch above the chart: Anomaly colors each day by how far it ran from the historical normal for that date (red = warmer, blue = cooler), Daily mean temp shows the absolute mean temperature for the day (useful to see seasons and heatwaves), and Precipitation shows daily rainfall (useful to spot wet/dry seasons and droughts). Normal = the long-term average for that calendar date (1940–2026).