Do Tarantulas Predict Weather?

One of the stories I've always heard as I grew up on the ranch, was that various things indicate when a storm is due, if it's going to rain, etc.  One of those tales is that spotting a tarantula spider is a good indicator that a good rain is coming soon.

The theory is that the spider is expecting the rain to flood their underground home and they are out looking for dry nest.  There well may be other reasons, but I'm not aware of them.

In the summer of 2015, I had been assigned to the Rough Fire, burning southeast of Shaver Lake. One of the runs assigned to the drivers was to take hot meals to the Kirsch Flat spike camp along the Kings River. This camp was several miles east of Trimmer above the Pine Flat Reservoir.  This required the driver to arrive at the spike a little before 6:00 PM.  By the time we got unloaded, picked up anything the had to go back to the main fire camp at the old Dinky Creek Mill, it was approaching dusk.

As we drove along the twisting road from Trimmer to the spike camp, a distance of eight or nine miles, we began seeing the occasional tarantula walking across the paved road.  The only time we'd see the big black spiders was moments before full-dark on our way back to fire camp. When we did see them, there were only one or two on the entire trip.

The drivers started talking about the occasional sightings. The general consensus was that even though it was late summer, a rain could happen anytime.  This area of California often gets a northern flow from Baja in late August. And these so-called "monsoonal flow" storms will indeed dump a little rain.

When the tarantula sightings became more and more frequent, as many as ten or fifteen per trip, we decided it must be going to rain, even though the weather was hot and dry. But when the sightings of tarantulas parading across the road began to happen earlier in the day, often several seen on every trip, we were certain the rain was imminent.

This big spider was spotted in full daylight, prancing across the road.

The night this big bug was photographed, it rained during the night.  In fact, it rained for most of two days. Sadly, it didn't rain much on the fire, but fire camp got thoroughly soaked. As far as the drivers on the Rough Fire were concerned, the tarantulas had told us it was going to rain, and it certainly did.

I used to write a column for the local newspaper, and often wrote about things that happened to me, such as the tarantulas.  I suggested that seeing the big spiders walking around wasn't an iron-clad predictor, but simply one of many things the Indians and old-timers used to anticipate the weather. I put the above picture in one of my columns, and sent it in.

I immediately had one woman write a letter to the editor, stridently stating my claim of a tarantula being able to predict an impending rain had absolutely zero basis in fact. She suggested the real reason was the spiders were preparing to mate, and were wandering around looking for a potential mate.

I suppose there is certainly some truth in that claim. Of course, my question would be how come the tarantula most often is seen out walking just before a rain?  Is it possible that Mrs. Tarantula becomes more amorous when she can hear the gentle sound of rain?