(The picture, showing temps with elevation, in this article is KEY to look at; otherwise it would be next to impossible to follow this technical blob of data you’re about to read).
NORTH HAVEN- My special interest in weather tends to revolve around microclimates and correspondingly, elevation. I have a professional handheld weather station called a Kestrel 3000 (~$250). With my prior knowledge of knowing how valleys and radiational cooling work, I decided to go out and test how much just a few feet can actually affect extremely localized temperatures- ‘neighbor to next door neighbor differences’. My street, Welch Road measures exactly 0.28 miles long- roughly a quarter mile. The bottom of my street (Mill Road end) starts at about 70’ elevation. It gradually rises to 100’, the crest of the hill which happens to be my house, but then, however, it dips back down to 90’ just for a few houses before climbing back up to 110’ at the top of the hill. My house to the top of the hill is only 200’ apart- I need to stress that we are talking about a minuscule difference in distance here. At nighttime (generally calm conditions), cool air normally settles into the lowest spots in the general area- the valleys. On Sunday night just after 11pm, I went up and down my street multiple times to prove this theory and my data supports this idea without a doubt. Let’s start at the crest of my hill; It is 65.9 degrees at 100’… head east and in the dip, the temp bottoms out at 65.2 just 10 feet lower than my house. Then you walk 75’ or so up the hill to an elevation of 110’ and the temperature is 66.8 at the highest point on that road. Walking backwards, the senor drops to 65.3 (very close to the original reading) in the dip and bounces back up to 66.1 at my house under a hundred feet away. Going west over the crest of the hill (in front of my house) and dropping slowly in elevation, so does the temperature. After passing the intersection of Welch and Stanford, although the elevation is still dropping, the temp rises as we approach a main/busy road which is reasonable. The temp bottoms out at 65.3 again, now at the bottom of Stanford Lane on Welch Rd at 85’ elevation (just 150’ or so from my house). Walking up the hill, the temperature reaches 67.3 where the rise levels off now at 120’ elevation. Going back down the hill and reaching the bottom, the temperature says 65.6 (85’ elevation) and heading east again back towards my house, the handheld re-rises to 66.0 degrees. This article may be hard to follow, but it is a very good example of how the smallest change in elevation and even how the weather in the littlest valleys can be so different. Temperatures can very all up and down your street no matter what the size of the road is- elevation and whether you’re in a valley or on a hill (actual height doesn’t matter- just the formation of the land) is key in determining where the cooler temps may be, vice versa, warmer temps. Thanks for reading and following along!