Climate in Benicia

Moderate Mediterranean weather resulting in dry, warm Summers and moderate Winters. The mean annual temperature is 69 degrees with an average annual rainfall of 18 inches. Located on the waterfront, the City benefits from cool ocean breezes year round. 

The climate is temperate and Mediterranean, resulting in dry, warm Summers and moderate Winters. Rainfall averages nineteen inches and falls mostly from December through April. The mean annual temperature is 63 degrees with prevailing winds from west to southeast.

Temperature Averages in Benicia


Yearly Weather Determines Our Gardening Zone

Benicia is probably in Sunset zone 15, unless it's in zone 17, and wanting to be in a different zone doesn't make it so.

After a week of fog and cold, the rain was a welcome sight, bringing with it the hope and promise of clear skies ahead.  It was good for the garden to have the fog (I hate watering in the winter!) but the garden prefers a few winter rains.

This week’s comes from a friend planning a garden with some frost tender plants.

Q:  Which Sunset zone are we really in?  I have heard that we are in 17 and 15.  What difference does it make?

A: There is a talented horticulturist named Sean Hogan who owns Cistus Nursery near the boarder of Washington and Oregon.  His web site at one time touted the concept of zonal denial.  It is a common practice, one which gives many a gardener great joy.  Many of us have pushed that envelope, often with mixed results.  Benicia is on the line between 15 and 17, with a little 14 thrown in for good luck.

I used to think I really wanted to live in the land of zone 17.  Oh the plants one can grow, including the beloved Tibochina urvilliana (Princess Flower)!  But, in fact the signature of zone 17 is summer fog, think San Francisco or Point Reyes. With an average summer temperature of 60 to 70 degrees, it is challenging for tomatoes or even Gardenias.  So I have amended my scope - I like some summer heat.

Zones 15 and 16 are colder in the winter with warmer summers, where one can grow plants that demand summer warmth and a bit of the winter chill.  That means not only are Gardenias a go but you can have an occasional Peony!

I think for the Bay Area, zones 15 and 16 are really a great deal, the best of it all locations.  Here you will find morning fog in the summer, burning off early to nice warm (sometimes hot) afternoons but the winter temperatures will be a little colder than zone 17. 

So where are the lines drawn and what happened to zone 16?  Zone 16 does not extend quite to our little town.  It extends into the ridge tops of Contra Costa and Marin Counties.  We have just a bit too much valley influence to support a zone 16, however, if you want to name a micro climate in your yard zone 16, go ahead.  You too can participate in zonal denial!

So zone 15 really dominates our location.  The line of demarcation is not distinct but you probably suspect where you have landed.  If you get up on a fine summer morning and look down onto the strait to see the fog below, you are most likely in zone 15, your tomatoes thank you, your gardenias thank you.

What about zone 14?  Ah, that would be only the part of town touching and influenced by the air currents of Richardson Bay.  It is Zone 14 because of the additional heat and cold.  It has less costal influence and more inland heat.  It is most likely to be mistaken for Cordelia. 

What does this mean?  It means little, just a couple of degrees one way or the other!  If you are a zonal denial gardener (you know who you are), you will need to be careful where you plant your plants. 

Need more heat?  Plant those Gardenias along a sheltered south west facing wall.  Need more winter chill, find the lowest coldest (exposed to the winter sky) spot in your yard for the Peonies.  Because we are riding the fine line of zones, these are good ideas anyway.  You never know if we will have a zone 15 or a zone 17 year until the year has passed. 

Have you trimmed the roses?  If not, this is the time to do it. Wait until there will be no rain for a couple of days and go ahead.  Oh yeah watch for slugs, they are really slimin’ up the place lately.   See you in a couple of weeks!

Alison Fleck is the owner of Simply Perfect Gardens, a Benicia based landscape design company

About this column: Alison W. Fleck is the owner of Simply Perfect Gardens, a Benicia based landscape design company.

Original article published in the Benicia Patch: