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Ya'an weather by month: averages, rainfall & climate trends

Ya'an has well-marked seasons, with 19.6°C between its warmest and coolest monthly means. Rainfall is strongly seasonal: the bulk of the year's rain falls between June and September. Ya'an weather by month: average temperatures, rainfall, extremes and how the climate has changed since 1940.

Today vs average

+2.7°Chigh above average

22° / 14°Today
20° / 15°Average
see today in detail →

How it's changed

+1.2°Caverage temperature, 2016–2025 vs 1940–1949average temperature vs 1940–491frost days a year now (2016–2025) · 14 in the 1940sfrost days a year · 14 in the 1940s50days above 30°C a year now (2016–2025) · 18 in the 1940sdays above 30°C · 18 in the 1940s+1.2°C vs the 1940s · see how it's changed →
Weather by montha typical year, averaged over the full recordJanuary, rain 60 mmhigh 9°low 3°February, rain 66 mmhigh 11°low 5°March, rain 92 mmhigh 16°low 9°April, rain 122 mmhigh 21°low 14°May, rain 145 mmhigh 25°low 18°June, rain 202 mmhigh 27°low 21°July, rain 367 mmhigh 29°low 23°August, rain 378 mmhigh 29°low 23°September, rain 231 mmhigh 25°low 20°October, rain 128 mmhigh 20°low 15°November, rain 91 mmhigh 16°low 10°December, rain 59 mmhigh 11°low 5°wettest month August, 378 mm · 1,939 mm a yearsee month by month →

Right now

What it's doing today vs the historical average for this date.
Clear

Right now

22.2°

21°feels like
48%humidity
11°dew point
8 km/hfrom E
UV index3.6
sunrise07:12sunset18:33day length11h 21m
TodayClear22°14°
TueMostly clear25°16°
WedOvercast19°16°
ThuOvercast18°15°
FriPartly cloudy22°15°
SatOvercast19°17°
SunOvercast20°17°

On this date: October 19

Today (forecast)
22° / 14°
Average for October 19
20° / 15°

High above average · +2.7°C

  • Highest since 1940: 25.8° · 2015
  • Lowest since 1940: 9.5° · 1987
  • One year ago: 19° / 16°

Every October 19 in history, coldest to hottest

▲ Daily highs▼ Daily lows

Dots show daily highs (top) and lows (bottom) for each October 19 on record (n = 87). Outlined dots are today's forecast.

Area we sample

Each city's history comes from one ERA5 grid cell, about 28 km across, shown by the dashed box. Near mountains or coasts, conditions can vary across the cell.

Location & data

Historical weather for Ya'an is sampled from the ECMWF ERA5 reanalysis at 29.99°N, 103.00°E, with daily records since 1940.

Coordinates
29.99°N, 103.00°E
Time zone
Asia/Shanghai
Period
1940–2026
Data source
ERA5 (ECMWF)

Last 30 days

28 of the last 31 days were warmer than the historical average for that date. Average difference: +1.5°C.

Each bar is one day, from morning low to afternoon high. Warm-colored bars are days whose mean ran above average; 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. Average = the day's mean temperature averaged across every year of record (1940–2026) for that calendar date.

This date over the years

One dot per year, showing the mean temperature on this calendar date. Dots are warmer or cooler than the long-term average (dashed line); the shaded band is the typical 10–90% range, and the highlighted dot is today's forecast. Based on ERA5 reanalysis: modelled estimates, not station readings.

Weather by month

Average temperatures and rainfall for each month: a typical year, from the full record.

Climate overview

July brings the year's peak warmth, with afternoons typically reaching 29.1°C and nights around 23.1°C. On about 115 nights a year, the temperature never drops below 20°C. At the other extreme, January brings afternoon highs of about 9.5°C and typical overnight lows of 3.0°C.

Ya'an picks up roughly 1,939 mm a year, with a peak of 378 mm in August and as little as 59 mm in December. A typical year brings rain or snow on around 181 days.

The record here starts in 1940, and since then the annual mean in Ya'an has climbed 1.2°C from the first ten years to the last ten. Days above 30°C have grown noticeably more frequent, from around 20 a year in the first decade to about 50 in the last.

Climate graph (climograph)

July is the warmest month, January the coolest: a yearly swing of 20°C. Wettest month: August (~378 mm). Whole year averages ~1,939 mm of rain.

Bars = average monthly rainfall (right axis). Lines = average daily high and low (left axis). Average = each month's value averaged across every year of record (1940–2026).

Rainy days by month

About 181 rainy days a year: most in August (~21), fewest in December (~10).

Bars = average number of days with ≥ 2 mm per month. Hover for the monthly rainfall total.

Monthly wind

Average daily peak wind at 10 m, by month.

Monthly solar energy

Average daily incoming solar energy in megajoules per square metre: the record's own proxy for how sunny the month is.

Ya'an month by month: what to expect

Typical conditions for each month, averaged across the full record (since 1940). Daylight is the time from sunrise to sunset. Highest and Lowest are the most extreme values in the ERA5 dataset (modelled since 1940), so they can differ from official weather-station readings.

MonthAvg highAvg lowRainRainy daysDaylightHighestLowest
January9.5°3.0°60 mm1110.3 h18.1° (1966)−12.2° (1955)
February11.5°4.9°66 mm1211.0 h23.7° (2021)−13.8° (1945)
March16.4°9.4°92 mm1411.8 h29.4° (2025)−4.2° (1986)
April21.2°14.2°122 mm1412.7 h31.9° (2019)4.5° (1969)
May24.6°18.2°145 mm1413.5 h33.7° (1980)9.1° (1990)
June27.0°21.1°202 mm1513.9 h35.2° (2011)15.2° (1997)
July29.1°23.1°367 mm2113.8 h37.1° (2022)16.3° (1989)
August28.8°22.6°378 mm2113.1 h36.7° (2022)16.5° (1984)
September24.7°19.7°231 mm2012.2 h35.0° (2024)13.0° (1946)
October20.2°15.4°128 mm1711.3 h30.1° (2016)5.0° (1986)
November15.9°10.4°91 mm1310.5 h26.3° (1979)−0.3° (1976)
December11.1°5.0°59 mm1010.1 h20.9° (1968)−11.1° (1975)

How it's changed

Year-by-year signals from 1940 to today.

Climate stripes

Annual mean shifted from 1940–1949 to 2016–2025 by +1.2°C.

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

Annual mean temperature

Long-term trend: +0.14°C per decade.

One point per year, showing 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.

Seasonal warming

Dec–Feb is warming fastest: +0.20°C per decade.

Each faint line is one three-month period's average per year; the bold dashed line is its long-term trend. Different parts of the year often warm at different rates. Based on ERA5 reanalysis: modelled estimates, not station readings.

Hot days vs frost days

Days ≥ 30°C per year: 18.4 early in the record → 49.6 recently. Frost days: 14 → 1.

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. Average = a centered 5-year rolling average to smooth weather noise.

Yearly hot & cold extremes

Hottest day since 1940 in 2022, coldest in 1945: 37.1°C / −13.8°C.

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

Annual rainfall

~1,939 mm/year on average. Last decade: −10% vs that average. Long-term trend: −100 mm per decade.

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

Day-by-day grid

Each tiny square is one calendar day across the full record, about 30,000 days per city. Use the mode switch above the chart: Anomaly colors each day by how far it ran from the historical average 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). Average = the long-term average for that calendar date (1940–2026).

Frequently asked questions about Ya'an

Which is the warmest month in Ya'an?
On long-term average, the warmest month in Ya'an is July (mean daily temperature of about 25.9°C) and the coolest is January (about 6.3°C).
How does today's temperature in Ya'an compare to the historical average?
On October 19, 2026, Ya'an is forecast to reach a high of 22.3°C and a low of 14.2°C. The long-term average for this date (the full record since 1940) is a high of 19.6°C and a low of 15.3°C, so today's high is 2.7°C warmer than that average.
How much has Ya'an warmed since 1940?
Comparing the first decade of the record (1940–1949) with the most recent (2016–2025), the annual mean temperature in Ya'an is about 1.2°C warmer.
How much does it rain in Ya'an?
Ya'an receives about 1,939 mm of precipitation per year on long-term average, with August typically the wettest month.
What is the average temperature in Ya'an?
Over the full record (since 1940), the annual mean temperature in Ya'an is about 16.9°C. The warmest month is July and the coolest is January.
What are the average temperatures in Ya'an by month?
Average daily highs and lows for each month in Ya'an (°C, full record since 1940): January 9°/3°, February 11°/5°, March 16°/9°, April 21°/14°, May 25°/18°, June 27°/21°, July 29°/23°, August 29°/23°, September 25°/20°, October 20°/15°, November 16°/10°, December 11°/5°.
What is the weather like in Ya'an in summer?
Summer in Ya'an (June to August) is wet and warm. Daytime highs sit at 27–29°C and nights at 21–23°C; July is the warmest month. Rain picks up through the season: 15 rainy days and 202 mm in June, 21 days and 378 mm in August. No season is wetter.
What is the weather like in Ya'an in winter?
In winter, December through February, Ya'an is on the cool side. Afternoons run 9–11°C and nights 3–5°C; January is the coldest month. Rain falls on about 11 days a month, adding up to around 61 mm. No season is drier.
What is the weather like in Ya'an in spring?
March to May is spring in Ya'an, and it is wet and mild. March is still 16°C in the afternoon and 9°C at night, May already 25°C and 18°C. Rain rises from 92 mm in March to 145 mm in May.
What is the weather like in Ya'an in autumn?
In autumn, September through November, Ya'an is wet and mild. September is still 25°C by day and 20°C at night; by November it is down to 16°C and 10°C. Rain eases through the season: 20 rainy days and 231 mm in September, 13 days and 91 mm in November.
How many days a year does it rain in Ya'an?
On long-term average, Ya'an has about 181 days a year with at least 2 mm of rain or snow. The annual total is roughly 1,939 mm.

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