Less Rain and More Mosquitoes, Does that Even Make Sense?


Mosquitoes need water to complete their life cycle… so you might suspect drought years would be good for mosquito problems. But, the opposite is, in fact, true.

Warmer climates and stagnant, dirty water in our urban environments provide ideal conditions for mosquitoes to lay more eggs. In densely urban areas like southern California, mosquitoes can find water on almost any property – both above and below ground. Less rainfall means that any water sitting around tends to become more highly concentrated with pollutants and nutrients, and mosquitoes love that.

People tend to water their yards more which creates more runoff to travel down gutters and into the underground pipes. But more importantly, fewer rainstorms mean that trash and debris that collects in those undergrounds doesn’t get flushed out and causes runoff water to puddle and breed mosquitoes.

And, as California struggles to find solutions to conserve water, many residents are using rain barrels. However, if not properly maintained, the rain barrel can create the perfect environment for mosquitoes. Having mosquitoes invade your yard is not a pleasant way to enjoy your weekend barbecue this summer.

What can you do?

Are you trying to do your part by saving water? We appreciate that!

There are several ways to conserve water without inviting mosquitoes:

  1. We encourage drought-tolerant yards and urge you to switch to drip systems wherever possible to eliminate runoff.
  2. If you collect rainwater in barrels or buckets – be very careful – if they are not tightly sealed, mosquitoes will get inside and happily reproduce. Use tight fitting lids on buckets and rain barrels or cover them with a fine-mesh screen secured with a bungee cord. Check these regularly since they tear easily. If your rain barrel is attached to your downspout, a unidirectional valve or tight screening is required at the top to prevent mosquitoes from traveling down the spout and entering the rain barrel.

Every little source adds up. Do your part to protect your neighbors from mosquito bites and disease risk, and stay ‘Skeeter Safe!


By: Kelly Middleton, Director of Community Affairs and Helen Kuan, Outreach Assistant