I would spend $5.00 and buy one. The same thing is used for cooking too.

Yes. Soil type plays into it in a big way! Soils that contain more clay warm up slower than soils that contain more sand for better air space between particles:D

Vera

A meat thermometer works great. The same point that jabs into a roast turkey pokes into the soil fine. And I'd have no trouble using it in my kitchen again after a quick cleaning. You can even bury the end of an "air" thermometer in the soil in a pinch. It takes a bit longer to come to a true and stable temperature, but it works. I've picked them up at the local dollar store for use with groups of kids.

Your air temps sound like they would warm the soil. Carrot, radish, pea, beet, and spinach seeds are some that would do well at cooler temps. Also onion sets or plants and seed potatoes would grow with cool soil. It might be best to check with some gardeners in your area, though. I have no idea what New Mexico weather is like.

Frdnicholas, other factors are soil moisture and shade.

I've used a number of different thermometer types.

Cooperative extension may well track soil temperatures in various locations in your state. But, you'd need to do some searching of agriculture weather sites.

Steve

Here is a link that might be useful: Days to Germination for Vegetable Crops at Various Temperatures

I love how someone post-bombs a 13 y.o.thread by misreading the question and then insulting the responses. And they signed up to Houzz just to do so !!

HU and a bunch of numbers, if the OP took the trouble to provide outdoor temperatures - not indoor ones - why would you think they need to know indoor soil temps? Which will always hover right around whatever room temperature may be..,,,,duh!!

Many direct sow seeds for their gardens and actual *soil* temperature are often critical for successful germination. But inground soil temps do not have a direct correlation to ambient air temperatures. They cool much more slowly in fall and heat up much, MUCH slower in spring. And they are also impacted by soil type, moisture content and a variety of other factors. What everyone else already stated :-)

And no, you cannot accurately assess inground soil temps without a thermometer!!

A fair, but old question. If there were no sunlight, and no underlayer of soil, yes, the soil temperature would be the mean day and night temperature. But in the sunlight, the top layer of soil can get hotter than the daytime air temperature. Also the underlayer of soil will either heat or chill the top layer, depending on the season. So, in practice, it depends. You can stick your finger down a few inches in the soil and get a clue. But a thermometer is best.

Syngenta has a nice tool that seems to be reasonably accurate for me.

https://www.greencastonline.com/tools/soil-temperature

There is, BTW, a predilection in this forum for resurrecting ancient posts, thereby avoiding any ownership of the original question.

I would say knowing the soil temputate in Albquerque on a given day is not going to help you know when to plant outside. The weather here is extermly erradic and one can suddenly have a overnight frost , there is a big diffenrce in when the last chance of frost is depending on the elevation you are planing at. The river is at about 5200 feet but the homes in the foot hills are as high as 6400 feet. Better to look at the state extention offices website for last day of frost for your neighborhood. I say this having lost plant starts to a late frost many times.

What depth of soil does soil temperature refer to?

Soil temp and air temp are different things. You lose plants from a late frost because of air temp, not soil temp. This is a VERY OLD question about seed starting, which is about the *right now* soil temp. An overnight frost won't change the soil temp much, as the ground is a good insulator. Average daily soil temperature is quite stable. As I said two years ago, the Syngenta website is a good one to use for *right now* if you don't have a thermometer. But again, you don't score any points for resurrecting ancient posts.

BTW, as an aside, we've had ridiculously high temps down here for the past month or two, and our 24-hour average soil temp is now well over 100F! Have never seen it that high. We do watering not just to wet the soil, but also to cool it.