Hi everyone,(adsbygoogle = window.adsbygoogle || []).push({});

I was wondering if anyone could help me better understand dependent probabilities. I am interested in working out the daily chance of rain given the hourly chance's of rain.

Historically I know that on a given hour the chance of rain is 0.1. My first approach to work out the day chance of rain was:

P(rain during some time in the day) = 1-P(no rain during any hour)

= 1-(1-p)^24

= 0.9

However I know that the chance of rain on a given day is 0.4, significantly lower. I released hourly rain must be depended on other hours so. So for two hours I would do:

P(rain hour 1 or rain hour 2) = P(rain hour 1)+P(rain hour 2) - p(rain 1 and rain 2)

However doing this for 24 hours gets messy very fast.

Any ideas of how I could go about solving this sort of problem?

Thanks Matt

**Physics Forums | Science Articles, Homework Help, Discussion**

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Chance of daily rain from hourly rain probability

**Physics Forums | Science Articles, Homework Help, Discussion**