What is the Weather Like in Cancun in January or March or ???

I used data from the Mexican National Weather Service (Servicio Meteorologico Nacional) to compile information that can help answer this question.  For Cancun the records go back about 20 years.

So just how hot is it in Cancun?  The chart below shows the average high and low temperatures and the record high and low temperatures for each month.  As you can see the average high temperature is 90 F or above from April through September.  The hottest month is August with an average high temperature of 95 F. The "coolest" month (January) has an average high temperature of 83 F.  Only the months of December, January, and February have an average low temperature below 70 F.  The record high was 107 F on August 14, 2003 and the record low was 49 F on March 12, 1996.

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So you want to know whether to expect rain and how much?  The chart below can help with that.  This shows the average monthly rainfall and the most rain that has occurred in each month.  On average, Cancun receives about 51 inches of rain per year.  Almost half of that total (about 23 inches) falls in September, October, and November.  That 46.8 inches of rain in October happened when Hurricane Wilma hit the Yucatan Peninsula in October, 2005.  The driest months of February through April only receive about 5 inches of rain for the whole 3 months.

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What about the chances it will rain on any day and the most that has ever fallen on a particular day?  The chart below shows the average number of days that Cancun receives rain in each month. There is at least a 1 in 3 chance of rain on any day in June, and September through December.  And over half the days in October normally getting rain.  The driest months of February through April only get 4 - 6 days with any rain.
The chart also shows the most it has ever rained on any day in each month.  Once again, you can see that in October there was a day that got over 30 inches of rain.  The was the day that Hurricane Wilma hit Quintana Roo on October 21, 2005.

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To get the current forecast from the Mexican National Weather Service for Cancun, click here.