Unless you plan your wedding in less than a week, it is pretty impossible to predict whether or not it will rain on your special day.
The next best alternative is to look at the driest days in your city’s history.
I did this analysis for Houston, TX, because that is where many of my readers are. But I would like to do this for more cities.
I retrieved daily rainfall data (spanning January 1, 1947 to February 7, 2013) from the NCDC (National Climatic Data Center).
Each day of the year has 66 or 67 observations. This corresponds to 66 or 67 years. If the day of the year has not yet occurred in 2013, then that day has just 66 observations. (Leap year has just 17 observations, because we have had only 17 leap years since 1947.)
For each day of the year, I totaled up the number of times that day had measurable rainfall (>0 inches).
For example, let’s look at February 14. It has rained on 18 Valentine’s days out of the 66 Valentine’s days in our sample..
Here are the results of my analysis. Below (left) is a table of the top 10 driest days since 1947. You’ll notice that the first one is February 29, which is leap year. This made the top of the list because there just aren’t many leap years. (I debated on taking it out of the analysis altogether, but I ended up keeping it. )
Below on the right are the top 10 wettest days. These are days you may want to take your festivities indoors.
So, if you want to plan an outdoor wedding or other special event in Houston, it looks like your best bet would be one of these days above (left) (minus leap year). OF COURSE this doesn’t mean that it can’t or won’t rain on June 13 next year. But, based on the past 66 years June 13th does seem to be one of the dryer days.
Here is how the other 356 days in the year stack up.
Keep in mind that this is a pretty small sample (just 66-67 observations for each day). But, hey, this is the problem with weather data. It would be nice if we had data going back 1000 years, but we don’t. But, still, if you are a gambling man/woman then I would bet on the top 10 driest days.