Coldest it gets in Southern California (underwater)

[MrSam]

Being a new diver (15- dives) I have only had the opportunity to dive in a few places over the last 3 months. So far I have dived in Catalina, shore dive at Laguna, and shore dive at Newport.
The deepest I've gone so far was around 100 ft, where it began getting rather cold even in a 7 mil and thermal rash guard.

How cold does the water get during "diving season" in California.
I'm asking for 2 reasons essentially.

1. Do I need a cold-water reg/environmentally sealed reg?
2. When should I hang up the dive gear and call it a season? Which months are best to dive in?

 

[Lopez116]

A lot of people dive year round over here. Usually 50 is the coldest it gets (maybe a degree or two below that, but not usually). A lot of people opt for dry suits. Viz is best in the winter.

The water is warmest in the late summer and fall. I've dived at Catalina in late September with temps in the mid-70's. Usually, it averages a max of 70 +/- 2 degrees. Everyone has a different cold tolerance, but I don't wear a hood when its that warm.

P.S. You shouldn't be going to 100 feet with only 15 dives under your belt.

 

[MaxBottomtime]

Dive season is twelve months long in SoCal. Water temps vary by location and other factors. It has been in the upper 60s in Laguna Beach during July and at the same time it was 48° in Palos Verdes. In more than three decades of diving here, I haven't seen any colder than 46°. A sealed regulator is not necessary unless you plan to dive one of the local mountain lakes in February.
Generally, coastal waters and the southern Channel Islands will have water in the mid to upper 60s during late spring to mid fall. It is generally a couple of degrees colder in the Northern Channel Islands. September through November usually has the best visibility, but clear water can occur randomly at any time. We had blue water a half mile off Redondo Beach last fall. Spring brings warmer water, but it also brings algal blooms. Reduced visibility and green water is common from March through May.
During the winter, the water will be colder but conditions can be excellent between storms. After 800 dives in wetsuits, I finally broke down and bought my first drysuit twelve years ago. It was the best investment in diving I ever made.

Redondo Beach last fall

It's always dive season in Southern California

 

[Lopez116]

MBT, what causes blue vs green water? Algae/plankton in the water column?

 

[MaxBottomtime]

Yes. Right now is probably the worst time to dive here, although we had 35' vis last weekend. Sometimes there is so much "marine snow" in the water that you can't see more than a foot or two.

 

[mathauck0814]

Coldest water I've found in southern California down to 300+ feet is 48'F

1. No you don't need an environmentally sealed reg.
2. You don't ever need to hang it up for the season. That's more than half the reason to live here. Buy a drysuit and dive every weekend there isn't a small craft advisory.

 

[GrumpyOldGuy]

I have seen lower mid 40's at depth of San Diego. It does not make sense that far south, but it happens due to currents from the deep. Catalina always seems to be pretty warm on the other hand.

No on the sealed reg. Diving is year round on So Cal. The dry suite is handy for multiple and/or deep dives in the winter, mostly for comfort on the surface between dives. Not a requirement, but a nice option at times. The biggest difference for me between winter and summer there is the lack of crowds in the winter.

 

[drbill]

Diving "season?" We're not warm water wimps (although after 60 dives in the Philippines recently I'm becoming a convert). We dive year-round.

Low 50s is usually the coldest it gets within reasonable depth limits although I've experienced temps as cold as 46 F. Funny, I used to dive frequently to 200 ft for a filming project and never had a temperature below 50 F at those depths.

 

[Ramsy]

At recreational depths in southern California for general planning purposes, during the winter months, you should plan on diving in water that is in the low 50s. In summer, you should plan on diving in water that is in the high 50s.

 

[muzikbiz22]

Summer months, (now thru November), it's a 7 mil. Winter months, it's a 7 mil plus Lavacore for me. Was on the Yukon a month ago, and hit 49 F. No sealed reg, no cold water gear, etc. I have found the best diving to be at Catalina, August through December. Great vis, warm blue water, (relatively speaking). My favorite day of diving last year was in September, Catalina. It was about 90 degrees out, gorgeous day, 80 to 100 ft viz, TydBol blue water, warm, and I had an encounter with a :shocked2::shocked2: Oops, I forgot I wasn't going to mention "my encounter" here in public