Mild
Average highs are around 23°C, so days are mild rather than hot.
September verdict
Half Moon Bay, California, United States in September
Weather score62Good
Good for holiday weather
Average highs are around 23°C, so days are mild rather than hot. Sunshine averages 9h per day, so bright days are a strong part of the month. Rainfall averages 7mm, which is relatively low for holiday planning.
September weather
Monthly averages
Temp
23°C
Rain
7mm
Sun
9h
Sea
15°C
Weather score
62
Good
Seasonal climate calendar
TemperatureTemp
RainRain
SunSun
SwimSwim
Weather scoreWeather score
Trip feel
Drier
Rainfall averages 7mm, which is relatively low for holiday planning.
Bright
Sunshine averages 9h per day, so bright days are a strong part of the month.
Cool sea
Sea temperatures average 15°C, so the water can feel cool.
Map
Weather map
Compare Half Moon Bay, California, United States with nearby places by weather score, rain, sun, temperature, and swim conditions.
Temperature
September23°C average high
September is one of Half Moon Bay's warmest months, with daytime heat above the yearly average.
Warmest monthsJune to October
This stretch sets the upper range for average daytime heat.
Rain
September7mm average rain
September is one of Half Moon Bay's driest months, making outdoor days easier to plan than in wetter parts of the year.
Driest monthsApril to October
This is the drier part of the year, when outdoor plans usually need less weather flexibility.
Sun
September9 hours average sun
September is brighter than Half Moon Bay's yearly average, though the strongest sunshine usually sits closer to the peak months.
Brightest monthsApril to August
This stretch has the strongest sunshine in the monthly averages.
Sea temperature
September15°C average sea
September is one of Half Moon Bay's warmest sea months, when swimming comfort is usually strongest.
Warmest seaJuly to October
Sea temperatures are usually near 14°C in this stretch, so swimming comfort is at its strongest.
Weather score
September62 weather score
September is one of Half Moon Bay's best weather-score months, combining the strongest overall balance in the yearly averages.
Best weather monthsMay to September
These months have the strongest weather score in the monthly averages.
