Climate averages 1991–2020

Perth weather
in May.

A mild, moderately wet month: the 8th warmest and the 9th driest of the year. Meets the pleasant-weather rule

Long-term climate patterns, not a forecast for a particular trip.

Average high 20.9°C Daytime mean, May

Average low 12.4°C Night-time mean, May

Rainfall 67 mm 8 days with ≥1 mm

Daylight 11 h Sunrise to sunset, per day

May is a mild month in Perth: daytime highs average 20.9°C and nights cool to about 12.4°C. By daytime temperature it is the 8th warmest of the 12 months.

Expect about 67 mm of rain on roughly 8 days, which makes May a moderately wet month (the 9th driest of the 12 months). Daylight, from sunrise to sunset, lasts about 10 h 31 min on an average May day.

The nearest other city in this atlas is Mandurah (65 km away). In May its highs average 20.5°C, about as warm as Perth, with 73 mm of rain.

Among the 32 cities listed in Australia, Perth ranks 12th of 32 for the warmest May highs and 22nd of 32 for the driest May (rainfall, lowest first). The mean May high of those 32 cities is 19.5°C; Perth is 1.4°C warmer than that mean.

From May to June, average highs fall by 3.0°C to 17.9°C, and monthly rainfall rises from 67 mm to 98 mm.

The annual picture

May in context

30-year average

Average highAverage low°C

Monthly rainfall

Average total · mm

Averages from hourly ERA5 reanalysis data. Actual weather varies from year to year. How these numbers are calculated

Every month, side by side

Perth climate table

1991–2020

Monthly climate averages for Perth, 1991–2020
Month	Average highHigh / low	Average low	Rainfall mm/month	Rain days ≥1 mm/day	Daylight hours/dayDaylight h/day
January	31.2°C18.8°C	18.8°C	17	1.8	14.014 h
February	31.2°C19.2°C	19.2°C	16	1.5	13.213 h
March	28.9°C17.8°C	17.8°C	17	2.3	12.312 h
April	24.8°C15.3°C	15.3°C	24	4.1	11.311 h
May, selected	20.9°C12.4°C	12.4°C	67	7.8	10.511 h
June	17.9°C10.5°C	10.5°C	98	10.7	10.110 h
July	16.7°C9.5°C	9.5°C	102	12.5	10.310 h
August	17.2°C9.6°C	9.6°C	89	11.0	11.011 h
September	18.5°C10.4°C	10.4°C	55	8.5	11.912 h
October	22.0°C12.2°C	12.2°C	27	4.7	12.913 h
November	25.7°C14.9°C	14.9°C	19	3.7	13.714 h
December	29.0°C17.1°C	17.1°C	9.3	1.6	14.214 h

Rainfall is the average of the 30 separate monthly totals. A rain day is a local calendar day with at least 1 mm of precipitation. Daylight is the calculated sunrise-to-sunset length, not measured sunshine.

Compare places

May in nearby cities

Distance from Perth

Read the numbers correctly

Climate, not a promise.

These patterns help compare months. They cannot tell you the weather on a specific day of your trip.

Sources, method and limits

How these numbers are made (what the highs, lows and rain days mean, the sources and the model cell used for Perth) is explained once on the Perth year overview and on the Sources, method and limits page.