Excerpts from Jim Conrad's
Naturalist Newsletter

from the July 20, 2007 Newsletter issued from Sierra Gorda Biosphere Reserve, QUERÉTARO, MÉXICO

Two weeks ago our rainy season suddenly turned dry again. For about a week we went without a single good shower. I mentioned the matter to Don Gonzalo and he said things would change with the Canícula. Canícula was a new word, so I looked it up.

It turns out that there are as many opinions about what a Canícula is as there are how a burrito should be concocted. Don Gonzalo says that this year's Canícula began on July 15th and will run for 40 days more or less to the beginning of September. The person who wrote the Spanish Wikipedia page about Canículas says it begins on July 20th and lasts until August 25th. Other sources suggest other dates.

Everyone seems to agree on this, however: The Canícula occurs -- at least in the Northern Hemisphere -- during the hottest, rainiest part of the year. Vegetation is lusher then, the bites of insects and reptiles are most venomous, skin wounds are most likely to fester, and people are most likely to get sick. That's how most people here think of the Canícula -- simply as the rainy period when natural things, especially those which can cause trouble, get more intense than usual.

I like Don Gonzalo's beginning date for the Canícula because on that date of July 15th, for the second and final time this year, the Sun passed directly above Jalpan. You'll remember from my May 26th Newsletter that on May 26th the Sun's ecliptic passed directly above Jalpan as it moved northward to the Tropic of Cancer, which it reached on the Summer Solstice, June 21st. Now as the ecliptic moves back southward it passed over us again on July 15th, on its way to the Tropic of Capricorn, exactly above which it will stand on the next Winter Solstice.

The word Canícula has good roots. It's based on the constellation name Canis Major: Canis --> Canícula. During the Canícula the Sun is in conjunction with Canis Major, which means that the Sun looks like it's passing among the stars constituting Canis Major. We can't see the stars because the Sun is so bright, but people who plot astronomical charts know what constellation the Sun is in even if they can't see the stars around it.

Also, the Latin name for the star we call Sirius, or the Dog Star, is Canicula.

By the way, on the day Don Gonzalo said was the first day of the Canícula, a downpour restarted our rainy season just as he'd said it would, and it's rained every night since then...