Today’s Podcast

We interview climate scientist Daniel Swain, who, besides being a University of California Ag and Natural Resources employee at the California Institute for Water Resources, is well known on social media. Swain runs the Weather West website as well as his frequent presentations talking about extreme weather conditions in California and the west on YouTube, Bluesky, and other social media outlets.

TIPS FOR SETTING UP A HOME WEATHER STATION

One common topic when two gardeners meet: the weather. Gardeners are usually grousing about some aspect of whatever is happening with the current weather: the heat vs. their tomatoes; the threat of frost to their citrus or succulent plants; gusty springtime northerly winds drying out the soil prematurely; and let’s not forget comparing plant damage due to a freak hailstorm.

Many gardeners are amateur meteorologists, with a yard full of devices that measure the air temperature, the rainfall, the humidity, the wind, and more. According to University of California Ag and Natural Resources climate scientist Daniel Swain, more care is needed as to where you place those weather sensors. After all, that thermometer that’s hanging outside your kitchen window may be reading much warmer than what is happening in your garden.

“There are genuine microclimates that can vary over that distance. If the thermometer is attached to your house, it might be warmer,” says Swain, who runs the informative Weather West YouTube page and on other social media outlets. “Presumably if it’s a cold night, you have the heater on inside. Some of that’s going to bleed outside a little bit near your house. If you have it hanging on a wall or an eave somewhere, it is going to exert perhaps a bit of a warming effect. And irrigation can affect the reading. Most people who are farmers or gardeners know that once you put water in the soil, once you put water on the plants, you kind of dampen the range of temperatures that you’re going to experience. By having moisture in some places more than others, you’re also going to actively, in some cases, create a temperature differential that’s different than where you might be measuring at your house or out on the driveway.”

Swain says more thought needs to go in to where you place that thermometer sensor for the most accurate readings for the plants of greatest concern.

“You’re measuring, technically, the temperature of a small increment of air immediately surrounding that thermometer device,” says Swain. “Imagine two different scenarios, the same parcel of land, the same home, and two thermometers within, five feet of each other. There’s not really a meaningful meteorological difference between the temperature across those five feet under normal circumstances. The numbers should be the same. But imagine that one of those thermometers is just sitting out there in direct sunlight. Maybe you’ve mounted it on a pole above a dirt field or over a concrete or asphalt driveway. That thermometer is going to read some awfully high values in the daytime and potentially some awfully low values in the nighttime. And that’s because you have the sun directly shining on the thermometer, heating the thermometer itself because of the sunlight is landing on the device itself. That thermometer is going to read a very high value. On a hot day, you might even get a value of 120 degrees on that thermometer. But as we define the surface temperature, the temperature at two meter height, so right around the top of my head, since I’m a little over six feet tall, that’s kind of a standard meteorological temperature measurement that’s used not just in science, but also for practical purposes and in agriculture and any number of applied purposes, that temperature is actually supposed to be a shade temperature. What you’re measuring is something different than the number that you’re comparing to everyone else’s numbers. When you go to the National Weather Service website and get a temperature forecast or you look at observations from official weather service certified meteorological stations, the temperatures you’re seeing are taken at the six-foot height in the shade.”

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TRANSCRIPT: Home Weather Station Setup Tips with Daniel Swain

Farmer Fred:

If you’re a longtime gardener, you just might be a weather nerd. You may want to know what’s happening, especially around your garden area and greenhouse, about many things, such as what’s the high temperature? What’s the low temperature? What about humidity, wind, soil temperature, rainfall, evapotranspiration rate?

Plus, there’s chill hours, growing degree days, heat index, UV radiation, and a lot more that can be affecting you and your plants. And your meteorological equipment right now may be as simple as a thermometer hanging outside your kitchen window, which may not be the best idea. We’ll have more about that in a minute. Or it could be as complex as a really nifty weather station that set you back $1,000 or $2,000 that sends a myriad of data to your computer or phone or your in-house monitor. So if you’re considering upgrading your backyard weather equipment, you also need to consider the placement of those various devices in your yard to get more accurate readings about what is really happening in your garden area, especially near your food crops. And you know something else? That upgrade that you’re thinking about with your weather equipment just might be a great move because of the recent cutbacks at the National Weather Service, where personnel and working hours have been slashed, including throughout a very wide swath of California.

Today, we’re going to get some answers to those questions from Daniel Swain. If that name sounds familiar, you may know him as the man behind WeatherWest.com. He’s a climate scientist focused on the dynamics and impacts of extreme events, including droughts, floods, storms, and wildfires. Daniel holds joint appointments as a climate scientist within the California Institute for Water Resources, which is part of the University of California Ag and Natural Resources, as well as the Institute of the Environment and Sustainability at UCLA. And he’s a research fellow at the NSF National Center for Atmospheric Research. He’s an alumnus of Davis and Stanford, and he completed postdoctoral work at UCLA. And again, his Weather West blog is excellent reading wherever you might be on social media, especially Twitter, Blue Sky, and YouTube, where he does presentations all the time about upcoming weather events. I’ve been a fan of his for years. Daniel, I’m finally glad to be able to talk to you in person. Welcome to the Garden Basics podcast.

Daniel Swain:

Yes, thanks for the invitation to be here today. It’s great to be on the show.

Farmer Fred:

All right. I’d be curious about your own home weather setup. What’s that like?

Daniel Swain:

[3:30 ] Ah, yes. I actually am based physically in Boulder, Colorado these days because of that NCAR appointment, despite the primary one with the University of California. So we don’t own a home here. So I’m somewhat limited when I can personally install on this side of the Rocky Mountains. But back in California, back when I was in high school, believe it or not, I installed a weather station on my parents’ home in the North Bay. And that is something that I have maintained over the years on their roof. It’s still there. It still gets maintained. And I’m still trying to use, to the best extent possible, best practices for meteorological station sighting on that one.

Farmer Fred:

I understand completely. I think when I bought my first large parcel of land, I got myself a Davis Instruments weather station, which was at the time one of the best you could buy. And that let me know a lot of things like wind direction, the high temperature, the low temperature, rainfall amounts, things like that. But it has gotten so much better over the last 20 or 30 years. And the data is much easier to comprehend as well because of either in-house monitors or the data is shot straight to your phone or your computer, it makes it a lot easier. But as they say in the computer world, garbage in, garbage out. So where you put that home station, no matter what kind it is, where you put it in your yard is very important, isn’t it?

Daniel Swain:

Oh, it’s incredibly important. And this is actually something that I think is not always as obvious for a lot of folks as it might be to some meteorologists, although perhaps not even to all the meteorologists in the world who haven’t worked a lot with actual physical instrumentation. And I think this is because, as you say, exactly where you put these devices and where they are relative to other things that might be in the immediate vicinity can make a huge difference into the numbers of the data you’re actually seeing in front of you. And, as you mentioned, there’s any number of different companies that manufacture weather instrumentation or packages of weather stations.

Daniel Swain:

For my part, just as was the case with you, the one I installed was indeed, I think it was one of the Davis Vantage Pro stations, sort of the best consumer grade ones that they o