Why is San Francisco cold and windy in the summer and warm in October?
338588
It's mainly due to the effects of ocean currents.  Water has a much higher heat capacity than dry air, so it takes longer to heat and cool.  So climates near major bodies of water tend to be more mild in both the summer and the winter than inland climates.
33065
The meteorological conditions: temperature and wind and clouds and precipitation
183470
Because wather instability happens whenever there is contrasting temperatures. In March, you have a cold air running up against hot air, so this causes there to be areas of low pressure.\n\nLow pressure = wind.
41191
Lately, the weather has been weird in Southern California (near Disneyland).  A few days ago it was really windy and warm.  Today, it was cool and sunny.  Tomorrow will probably be cool and sunny too.  In conclusion, I would say that it would be a pretty good time to come.  I don't think California ever really has terrible weather.  The worst that will happen is it becomes cloudy and might rain for a day, but by the next day, everything will be happy and sunny again.
986495
It's November right now in Boston and 40 degrees.  Its cold and its gonna a lot colder until around March when it will (hopefully) start to warm up.  The weather fluctuates all the time so you can never really be sure what the temperature will be.
535181
Yes. \n\nOn warm summer days, the air in urban areas can be 6-8°F hotter than its surrounding areas. Scientists call these cities "urban heat islands."
1072288
San Francisco, California, US
335783
There are a lot of great sites that give basic weather predicting information.\n\nDifferences in air pressure are what causes the fronts--high and low pressure. High pressure areas generally have dry, good weather and areas of low pressure have precipitation.
82882
cold and dry in the winter, rainy in April and hot and dry in the summer. Great weather from end of April til Mid September.
1165348
Because you are in the neighborhood of ocean. In the day when it starts warming up, the water in the sea evaporates and then the clouds come with wind. So it rains in the afternoon or the evening when there are enough raindrops in the clouds
215716
Concrete, glass, steel etc all absorb heat from the sun, when the temperature drops they act like radiators giving off heat.  The bigger the city the more heat it retains and so large cities such as Tokyo, London, New York can be several degrees warmer than the surrounding rural areas.\n\nIf you're ever out in a rural area on a cool night at the end of a hot day try walking on the road then walking on the grass - there's a marked difference in temperature - that's why cattle, sheep etc often congregate on roads in the evenings.\n\nCities also generate much more heat from motor vehicles, industry, heat escaping from buildings and even (to a small extent) the people in them.\n\nAdditionally, cities create pollution and this acts as a barrier which traps heat in and locks colder air out.\n\nThere's also the fact that cities tend to be at lower altitudes and for each 150m gained the temp drops by 1 degree C, and they're less windy than more exposed rural areas so it's harder for cold air to penetrate into a city.
49934
It depends.  Usually you will have the cooling effect as mentioned by the previous answer to to rarifaction of the air, but there's also the fact that the air being thinner leads to the top being more sensitive to changes, and the sunlight is less filtered.  The sun will feel hotter at high altitudes, and the last time I drove over Tejon Pass (which connects LA to the San Joaquin Valley), I noticed that the temperature rose as I ascended.  That same weekend, I check the weather report on the Kirkwood (ski resort) website, and they referred to an inversion, where the temperature gets higher as you go up.  I also know that at time camping in the mountains in the height of summer, it can be much hotter in the mountains than at sea level.\n\nDeserts are likewise often miisunderstood.  Generally we think of them as hot, but they can also get extremely cold because there's no moisture in the air to hold heat.  Some of the biggest deserts are in Antarctica.
386367
I'm guessing that you live in the Bradenton area, judging from your previous question. I live in the Ft. Lauderdale area. Right now is our late spring and now going into early summer. The humidity will get higher in May and the temperature will hang around 90 everyday, and that'll bring on the rainy season starting between late May and late June. It's just plain 'ol hot, humid, with lots of rain and sunshine all mixed together between June and October. If you're outside, you'll pray for a little seabreeze, which won't help much, but anything is better than 92-95 degrees, 70% humidity, and little wind. Bradenton has lots of afternoon thunderstorms in the summer (due to the seabreeze), so that'll cool things down in the evening. Oh, and welcome to hurricane alley.
565183
I'm originally from the north of England. The weather there is usually pretty mild but it can swing from being severely cold in the winter to being unbearably humid in the summer. That means that the average person has to own a lot of different clothes to deal with different weather. In winter we would wear long coats usually with some form of hood or carry an umbrella as a matter of course in case it rained. Sometimes it  rains there for days at a time and it can be very drizzly or very heavy. In summer everyone wears light clothing and on the hottest, most humid days we would end up wearing shorts and very light shirts. We took going outside for granted. It was normal to want to be in the fresh air!\n\nI lived in San Francisco for three years. The weather there is an almost constant 55 degrees. This means having a smaller amount of clothing and only needing some sort of jacket for the slightly colder winter days. Most of my clothing consisted of shorts and light, short-sleeved shirts. At the weekends the parks and public recreation areas would be completely full of people. The beaches around the area always filled up pretty quickly, even in the fall.\n\nI currently live in Las Vegas. The weather here affects every aspect of our lives. Because the temperature often reaches above 100 degrees, sometimes as high as 125 degrees, people tend to avoid going outside for long periods. People literally get in their cars to go somewhere inside where it's cool, get on with their business, and then get back in the car and go home. Any outdoor activity can be quite unbearable. Parks tend to be crowded in the early hours and after 5:00pm. It is insane to be outdoors in the mid-day heat. Drivers here tend to be on the insane side. People drive way too fast and I believe it has a lot to do with the unbearable hear. Sitting in a car can be most unpleasant, especially one that's been sitting in the sun for a few hours. Another way that people are affected here is because of the dryness. There is usually almost no humidity at all and coupled with the dust this makes for a very bad situation if you suffer from allergies. I've had a few reactions myself and I never suffered before. One way of avoiding the heat in the city is to make day trips to surrounding areas such as Mount Charleston where it tends to be 10-20 degrees cooler. I have to wear formal clothing for my job and I hate it. There are days when it's like sitting in a bath after I've been outside for a considerable time. My boss refers to it as, "sweating bullets." The heat makes for expensive living too as air conditioning is constantly on, in the office, at home, and in the car. During the winter in Las Vegas the temperature can be quite bearable an not too cold. This is when the parks see the most use and people will actually spend more time outside. It's actually exciting when it starts to rain, although we suffer from serious flooding in winter and people die.\n\nI have a couple of friends who are Canadian and they tell me stories of having to switch on their car engine block heaters to prevent damage. I'm sure there are areas in the north of the USA and Canada where it's normal to wear a coat everywhere they go and to want to be indoors for completely the opposite reason that we do. When I was in Chicago I found it interesting how my ears actually burned from being outside. I don't think I've ever experienced temperatures quite that low anywhere.\n\n--\nsf
915955
You have probably noticed that the jet stream, cold fronts, and that sort of weather all moves across the U.S. from west to east. What is happening is that New York, even though it is on the coast, is getting its weather from air masses that have come across thousands of miles of land, so the effect of being near the ocean is minimal. \n\nThis is only the case in big weather events such as fronts. On days where not much is going on, I suspect that the land/sea breeze dominates the daily temperatures and makes it fairly mild.
970970
This is not a simple answer to explain in one or two sentences, so I will give it in two parts.  First, the basic reason:\n\nOvernight, the breezy conditions that was on the surface is lifted upwards.  This is because the surface becomes very stable with the loss of daytime heating.  The wind will blow above this layer of stable air until after sunrise when daytime heating will bring the winds back to the surface.\n\nNow the more detailed explaination.  In general, wind at night will decouple from the surface if...\n-there is no strong subsidence (sinking of air) like what you will find behind a strong upper level disturbance.\n-there is strong mixing (unstable airmass) in and ahead of a storms system\n-there is strong surface winds with upper level support. (winds blowing from the same direction through a deep layer above the surface)\n-near ridge or hill tops\n\n(Assuming no major weather changes are expected to occur overnight...)  During the night, with the loss of daytime heating, we lose two parameters that will keep the winds blowing near the surface.  The thermal gradient usually becomes weak and the surface cools.  A thin stable layer forms near the surface as heat rises to the top of this layer.  With time, this layer will thicken as warm air continues to leave the lower layer and replace by cooler air.  The top of this layer, you will find a temperature inversion.  This layer will seperate the higher winds that has lifted higher in the atmosphere and the very stable and near calm winds below.  Once the sun rises, the surface warms and starts to mix.  This will break the inversion and the winds will start to mix back down to the surface.  \n\nThis is also the reason why during the winter, sometimes you will find ground fog forming in a thin layer during the evening and then lifting to a low cloud or stratus right by sunrise; then "burning" off during the day.
435903
Rain & Mudslides in the winter, Fires, hot and dry during the summer, unless of couse your in San Fransisco.