It’s not the heat that gets you; it’s the haze. Here’s why I didn’t ride this past weekend.

Smoke from Northern California fires blow hundreds of miles down the coast and into Bay Area. This smoke conspires with high ground-level ozone to create a nasty soup that’s difficult to breath for what the Bay Area Air Quality Management District calls “sensitive individuals.” This includes people like me with asthma. Even moderate activity triggered wheezing in spite of my medication.

Ozone is created by chemical reactions between nitrogen oxides, volatile organic compounds, and carbon monoxide in the presence of sunshine and heat. High ozone levels combined with high particulate matter (i.e. “smoke”) triggered weekend “Spare the Air” alerts, in which our regional air quality district asked people to limit their driving. The unusually high heat just before the end of summer break also motivated people to hit the beaches, which means hundreds of thousands of cars jammed our highways to the coast. Isn’t that a wonderful Catch 22?

The city of Santa Cruz, California is normally significantly cooler than inland areas, but this beach town unusually hit 101°F (38°C) on Saturday, smashing the previous record high for the day by an astounding 13°F (7°C). Sunday’s high was “only” 91°F (33°C), but that still beat the previous record for the day by 10°F (6°C). I’m sure the water felt wonderful on both days.

A Spare the Air Alert continues through today for the San Francisco Bay Area. I still biked to the office, but I kept my speed and exertion low.

What about San Jose Bike Train on Wednesday?

Temperatures should begin to cool by this evening, with air quality improving through the week. Ozone will drop to “Good” levels by Wednesday, when I have a San Jose Bike Train scheduled, but PM 2.5. (the fine soot smaller than 2.5 micrometers that passes the blood-brain barrier and may contribute to neurological decline) will still be at moderate levels as forest fires continue to burn throughout the state.

Bike Train runs rain or shine, and I will continue to ride daily, but I’m thinking about cancelling this week’s bike train because of the air pollution. What are your thoughts?