The offshore wind pattern of the past few days has spread very dry air over SoCal and has resulted in a very wide range of minimum temperatures in and around the San Fernando and Conejo valleys and the Santa Monica Mountains. Santa Ana winds blew all night long in many locales and resulted in mild minimums, while some wind-protected frost pockets were calm with frigid lows. Here are low temps for Thu and Fri morning, November 12 and 13, 2015, at selected stations in the San Fernando Valley, primarily the western SFV. Included are the familiar NWS stations and some private/home Weather Underground (WU) and MADIS stations which I consider trustworthy (at least on minimum temps!). low temps, flatlands SFV Thu Fri 40 48 Woodland Hills/Pierce College 36 42 western Woodland Hills WU (Woodlake and Victory) 39 58 West Hills WU (Roscoe and Woodlake) 39 44 Winnetka CW7387 (Sherman Way and Winnetka) 50 67 Chatsworth DW0345 (Plummer and De Soto) 58 65 CSU Northridge 45 49 Van Nuys AP 42 43 Van Nuys WU (Kester and Vanowen) 40 45 Burbank AP 42 44 Studio City DW6087 (Ventura and Colfax) 42 44 Encino WU (Ventura and Hayvenhurst) low temps, hilltop stations, Santa Monica Mountains and vicinity of SFV Thu Fri 56 63 Cheeseboro RAWS, north of Agoura, elev. 1707' 55 62 Topanga RAWS, south of Woodland Hills, elev. 1600' 55 63 Calabasas Park Belmonte WU, elev. 1438' 57 64 Malibu Hills RAWS, elev. 1575' 55 62 Porter Ranch above Northridge DW4339, elev. 1634' low temps, valley bottoms and frost pockets, Agoura/WLV/T.O. area and Santa Monica Mountains Thu Fri 53 66 Thousand Oaks VCAPCD (Moorpark and Avenida de las Flores, T.O. High School) 36 41 Westlake Village/Reid EW4921 (Hillcrest and Westlake) 32 39 Old Agoura WU 31 36 Agoura/Lost Hills WU 35 43 Bell Canyon WU 27 32 Lobo Canyon WU (south of WLV) 25 30 Paramount Ranch WU (south of Agoura, near Cornell and Mulholland) 30 msg Topanga DW5544 28 32 Malibu Canyon RAWS 59 67 Simi Valley VCAPCD The low temperature differences between the area hilltops and the coldest frost pockets on Thu and Fri are about as large as you'll see for this region. On Thursday, the coldest stations in the western San Fernando valley had mid-upper 30s, while the hilltops were in the mid 50s. At the same time, the outlying frost pockets were in the mid 20s to low 30s. The coldest stations are those in the well-protected low spots around Agoura. The Paramount Ranch station (which had 25F on Thu) is located a little bit north of and slightly higher than Paramount Ranch. The ACTUAL ranch may be even a little colder than this station, as it is closer to the valley bottom along the stream. On Thursday night and Friday morning the wind blew without interruption through Chatsworth, Simi Valley, and Thousand Oaks. Minimums were 66F to 67F at the stations for these places. At the Agoura-area frost pockets, protected from the wind, lows were 30 to 37 degrees colder! Paramount Ranch dropped to 30F this morning, 33 degrees colder than the nearby hilltop stations and 37 degrees colder than Chatsworth and 36 degrees colder than Thousand Oaks, both of which are similar in elevation. Malibu Canyon and Lobo Canyon were almost as cold on Friday morning, with 32F. The NWS often mentions Ojai as its favorite cold spot in Ventura County. The town usually has light winds during Santa Ana wind events, so the nights here are cold compared to the breezy areas. The NWS Ojai station is very close to the stream through the valley, and is an impressive frost pocket station. It dropped to 29F on Thursday, but that was still warmer than some of the Agoura-area stations. The other stations in the Ojai valley run several degrees warmer than the Ojai NWS station. low temps, Ojai area Thu Fri 29 34 Ojai NWS --- East Ojai WU elev. 773' 35 40 Ojai VCAPCD elev. 774' -- Ojai Ave WU 35 40 Ojai South Carillo Rd WU, elev. 758' 44 50 Ojai Fairview Road WU, elev. 1056' And, the point here, is that all of these valleys have isolated frost pockets and "cold spots" with impressively low minimums when the wind stops on clear and dry nights. The actual location of the weather station with regard to terrain and ground cover is a huge factor when it comes to how cold (or not cold) your favorite town is!