Southern California

[MattyB]

Last winter there were several threads where we would all check in every morning after a really cold one (weather that is not beer) and report our cold temps for the night.  I found the comparisons very educating and the info really helped me solidify my decision on where to live when Jen and I moved earlier this year.  So I thought I'd start this thread where us Southern Californians can congregate and report temps for comparison and education sake all winter long.  This way the temp info is all in one place instead of a bunch of random threads that always seem to get duplicated in multiple forums.  So SOCAL, lets give it a try and see how it goes.

I hit 45F this morning.  The low was actually around midnight before we got that backdoor rain sneak through and warm things up a bit.

[osideterry]

Nice idea Matt. I bet my lows are consistently 3-5F below yours.

My overnight low was 41F, thanks to the humidity and precip. I was starting to get nervous last night when I saw it was 42F at 11pm.

My forecast for tonight is 35F, lowest for the next 10 days, and would be my lowest so far this season by 3F.

[freakypalmguy]

Temecula, CA

32F for me last night. Been covering a few with frost cloth.

Matt

[happ]

47F in northeast LA this morning.  Actually the temp warmed up a bit after midnight when clouds moved over but no rain at my place.

[Shon]

Yeah last night was weird Sunday night I hit 37,then last night I was 47. Actually got a decent rain last night. Tonite looks frigid though.

[roosty sado]

Sup Shon?.....Matt......Brrrrrrrr....I got down to 49.7f last night but my low for the year is 41.......brrrrr.....it's rare that I'll ever drop lower than 39.Keep u posted.....Rusty

[paulgila]

roosty--yer not SHOUTING anymore!

anger management?

[Jim in Los Altos]

Can we make this a California thread rather than just a southern CA thread. I think it would be interesting to contrast our lows up here with your lows down there. By the way, my low this morning was 38.8F. The night started out windy and the temperature was still 50F when I went to bed at midnight. Tonight's forcast is 37F.

[happ]

Agree with Jim that posting of minimum temps include all of California.  Many was us have lived in N. Cal [Fresno/Chico/Vallejo/Salinas valley] & are interested in how the minimums contrast from bay to valleys  

This is a bona fide weather board  

If the models are correct than we will be comparing many cold nights temperatures    next week looks wet [heaven sent] but also cold well into the following week  

Hi: 67F/19.4c

[Kim]

I recorded 44.1 last night, but it's going to be cooler tonight.

[BS Man about Palms]

I was at 42F when I turned in at 12 pm and it was clear and cold and I was worried.  woke this morn at 630 to almost 43F and overcast, no rain though.

[BS Man about Palms]

46F right now at 830pm  trying to decide whether to "man up" and leave my palms out, or affect a rescue overnighter.

[paulgila]

41F last nite here in the deepest,darkest,lonliest pit of hades which i call home.

[ellidro]

48 at 1015 tonight.

[BS Man about Palms]

(ellidro @ Dec. 11 2007,22:07)

QUOTE

48 at 1015 tonight.

Nick- That sounds slightly warm for your place, is that monitor out in the yard or near the house?

[tropicalb]

I've got my hi-lo thermometer in the new greenhouse at my Dad's (YES I SAID NEW GREENHOUSE!!.....WOOOOOHOOOO!!!!), so i can't join in the fun reporting temps just yet, but suffice it to say it has been cold enough over the last few nites to break out the good ol' heater and set it up in my greenhouse out back. Lowest temp i hit the last few days in there was 40, and there are certain items that just flat DON'T like it that cold!

[mppalms]

I'm down in Orange County and San Diego a lot on business, and I must say this is the first time I've felt that it was about as cold at night as it is up in the bay area.  This is freaky California weather.  People down here said that the rain has been pretty hard, too.  We've had only a couple of inches total, I think.  It's all upside down.  But, the low for the season is 36 deg., which isn't half bad considering that we're almost halfway through Dec.

Jason

[Kim]

38.1 was the low at about 5:30am.  Now all the way up to 38.3.  It was 44 at 10:30pm, don't know how long it's been below 40.  Cold, but not endangering anything I have.

[BS Man about Palms]

36f at 630am still better than Jan 07!

[Palmhut1]

Vista is at 38 degrees.....

[osideterry]

Oceanside - Sal Luis Rey Valley, hit 37F, and is up to 38F. Not too bad

[ellidro]

42 was my overnight low and yes Bill the thermometer is in the yard about 10feet from the house.  I think I stated last year that Dypsis Dean was telling us he did an experiment with three thermometers all within inches of each other and all three had different readings with a range spread of 4 degrees.  Point being don't get too wrapped up over a degree or two.  I think noticing the degree of drop is more important than the actual number.

[bubba]

When is it going to heat up out there.Is not this a very strange winter for you guys?

[spockvr6]

Im out here in Costa Mesa for work and at 7AM it was 44F so not too bad.

[roosty sado]

Yea Nick.....wazzz up.Bill...Are you kidding...Nick has the best climate in S.D.,Except for Jessy.Better than mine.....but i got the buttery soil!!I got to 38.3 sometime last night and it was 41 at 6am....53.1 at 9am.Remember,I am shaded out....no sun.-Rusty

[MattyB]

I was 44F for my low this Wednesday morning.

At my dad's house in Lemon Grove he got 38F.

Bubba, I've lived in SoCal my whole life and this seems perfectly normal to me.  I always got many nights that hit around 31F - 33F while living in Lemon Grove which is sort of a flat, average spot for SD county.  It's usually dry on those nights that drop below freezing so we usually don't get frost and it rebounds quickly once the sun is up.  I really don't worry until it drops below 30F.

Jim, you should totally jump in.  If you make it relevant than it'll work great.  Shoot, Corey from UK can jump in if he wants, but that might be a stretch.

[freakypalmguy]

30F and a light frost. Nothing showing damage yet.

[epicure3]

Yes, it has been much colder than average the last 2 weeks. I bottoned out at 41 last night in my coldest location. I think it should be getting warmer from today on.....that would be nice!

[osideterry]

We have one more night of this. There was a layer of condensation on my car this morning. I think any moisture in the air keeps the bottom from dropping out in SoCal. Last January's freeze was accompanied by close to 0% humidity.

Sorry it means light frost for you in Temecula, Matt. Glad you aren't seeing damage.

[happ]

Interesting comments & very helpful in tracking minimums/topography  

Normal minimums for December are in the 40's:

LAX: 49F

Downtown: 48F

San Diego: 49F

I have found in 28 yrs of collecting data that December is actually the coldest month for minimums at my location [50F] due to the fact that the rain season often is stronger in Jan/Feb than Dec.  Thus the average minimums for Jan [51F] & Feb [52F]. In-fact December is the coldest month of the year even though the average maximum is one degree warmer than Jan [70F versus 69F].  It is only a faction of a degree though.

I have 3 thermometers & also notice how they can vary within 20' of each other.  I did not check all 3 instruments before going to work but one was reading 43F early this morning.

Epicure is correct that the last 7 days have been colder than normal.  The medium-range models are predicting continued below normal temps for the next 10 days    though minimums may rise above 50F by this weekend in metro Los Angeles.

[MattyB]

Thanks Happ, your stats & insight is always great.

Just a few things I've learned regarding temperature sensors through my own experimenting:

1.  Yes, they can vary a degree or two between different sensors or thermometers sitting in the same spot.  It's just a minor margin of error thing.

2.  They need to be out of the sun otherwise you'll get a false high temp.  Or don't mount it on the north side of a fence with the sun hitting the other side.  "Hey how come it was 120F today in December?"  Duh MattyB!

3.  Depending on the type of sensor, you will probably have to build a vented box (mount to a center post or shelf, not to exterior wall of box), overhang or mount it under a tree in order not to get a false low.  My "home base" station can sit out on a granite table in the open and still read correct because it's got a little foot base and I think the sensor is deeper inside the case.  My remotes cannot sit directly on a table or it catches some crazy cold surface temp from the granite table top so I have to mount them above the surface on a pole or tree.  They will read extraordinarily cold too if laying on their back facing the sky.  I spent many a night with several traditional thermometers and all my sensors figuring this all out.

4.  I think the official height to mount a sensor is 155cm or about 5 ft if I remember correctly.  I put sensors in different places, sometimes on the ground level to see what temps my little plants are actually seeing but I don't generally report these as these are site specific.

5.  A sensor next to the house or under the eves will consistantly read 5-8F warmer.  A sensor under heavy canopy will read warmer (and colder highs in summer due to transpiration).  So don't bury your sensor inside of a Ficus elastica mound and expect to get an accurate reading.

6.  Even if you try to take everything into account you'll still get different temps from sensors just a few feet away due to all the differences, and more, mentioned above.  I've learned to try and get a decent spot for it and try not to be too much of a perfectionist.

I hope that helps a little bit.  I didn't know any of this a couple of years ago when I started tracking my temps and wondered why I was getting such cold and hot readings.

[osideterry]

Build a vented box? I hadn't thought of that one.

Keeping a sensor out of direct sun, but not under any kind of eve or canopy has to involve some kind of compromise. I have mine mounted 5ft up on the north-facing corner post of my deck, 12ft away from my house. It gets slight canopy from the deck. I know it's colder farther from the house and out in the open.

[MattyB]

That corner post of the deck sounds like a good spot.  At least it's away from the house.

Here's a link that shows some easy enclosures you can make.  I guess they call them radiation shields.  It's as easy as cutting out the bottoms of a bunch of plastic bowls and mounting them w/ spacers to create a vented radiation shield.

radiation shield info link

And more specifically a Stevenson screen.  How to build using some plastic pot saucers (don't forget to paint white).

how to build stevenson screen

Maybe El Hoagie can show us the one he made.  It was sweet.

[elHoagie]

(MattyB @ Dec. 12 2007,13:22)

QUOTE

how to build stevenson screen

Maybe El Hoagie can show us the one he made.  It was sweet.

Matt,

I built my screen using the directions on the website you've linked to.  I can't seem to find a photo of it on my hard drive, even though I thought I posted one here on the board a while ago??

As far as the weather thread, my low has been the same the past two nights, 6.5C (44F).  The past few days I've seen some spotty frost on grass/cars when I go jogging in the morning in the "lowlands" around my house at 75m (200ft) lower elevations.  Thankfully it still hasn't dropped below 6C (43F) up at my place this year...

Jack

[roosty sado]

Ok,the latest at my place.1foot from the house west facing shade min(38.3)12ft from the house min(41.7).Im actually getting lower next to the house.So lets call it 40ish.Is the climate in San Diego changing?This isn't normal!

[Don Little]

(bubba @ Dec. 12 2007,11:32)

QUOTE

When is it going to heat up out there.Is not this a very strange winter for you guys?

Bubba

night time lows in November were a little higher than normal and daytime highs seemed about average.

December night time lows are on pace maybe slightly lower than normal as last night was the coldest low for me so far this fall/winter at 38.1 infact it was my first low in the 30's.  last year I had already experienced 3 nights in the upper 30's.

What really seems to be strange is that for the past week the highs have only been staying in the mid to low 60's with a few highs in the upper 50's.  

Going back to last years log we did have some stretches similar to this last year but we usually see plenty of 70's thruought the winter also to balance everything out.  Hopefully we'll see some of those coming up but it doesn't look like we can expect that for at least the next 10 days according to weather.com. but good news is that the lows should at least be back to the mid to upper 40's and perhaps higher closer to the coast.

Maybe Happ can chime in as to when we can expect some warmer daytime highs.

[Don Little]

38.1 last night here.  First night in the 30's so far.  Last year at this time I had already experienced 3 lows in the upper 30's so overal not to bad.

[Shon]

35.8 last night. Got to 67 by 11 though. I don't care as long as it is in the 30's I'm cool. I know what the breaking point is now. My gauge is in my coldest part of the front yard, so my prime growing spots in the back and side are at least 5 degrees better. It is a long time till spring though.

[Shon]

Rusty take care of my kingaly.

[Jim in Los Altos]

Brrrrrr...34F makes this morning the coldest this season. I wheeled my bottle palm (in its 20 gallon ceramic pot) into the garage last night and back out into the bright morning sun this morning. Tonight may be slightly warmer due to some cloud cover.