Weather Watch

Microclimate is perfect for local apples

If you do nothing but hang out by the ocean, you might think temperatures never change much in San Luis Obispo County.

A review of 30 years of meteorological data from Diablo Canyon nuclear power plant reveal only about a 7-degree temperature change from the average minimum low of 53 degrees overnight to the average maximum high of 60 degrees.

However, just slightly away from the immediate coastline, temperatures can vary greatly. Farther inland, North County valleys can see overnight temperatures reach into the single digits during the winter and more than 100 degrees during the summer.

These microclimates are critical for many of the crops that are grown along the Central Coast. One of my favorite local crops is the apples produced in See Canyon. Because of its unique microclimate, apples have been raised there for well over a century.

Edward Evenson of Creekside Farms told me that apples need a lot of chill hours during winter to set the trees and kill the unwanted bugs, but enough warmth in the spring to prevent frost.

See Canyon provides a near perfect climate for apples. On calm winter nights dense cold air flows downward along the slopes of the Irish Hills and accumulates at the bottom of the canyon.

Edward said temperatures can be nearly 30 degrees colder at the bottom of the canyon than on top of the ridge.

This condition often leads to below-freezing temperatures. In much of our state, there’s too little chill in winter and too much heat in summer for many apple varieties to flourish.

During the spring, the ever persistent and strong northwesterly winds coming off the Pacific Ocean keep frost from developing.

During summer, the fog-shrouded mornings provide enough moisture so that most farms don’t have to irrigate. On rare occurrences the canyon can heat up and produce scorching temperatures, causing the trees to drop their fruit.

In addition to a near perfect climate for apples, See Canyon has ideal soil. It is composed of serpentine, marine shales and clays of the Franciscan formation, with pH readings between 6.5 and 7.5.

More than one person has told me that these different types of minerals add to the wide range of flavors in the apples raised in the canyon, much like Central Coast wines. These See Canyon apples are crisp and tasty and the finest that I have tasted.

The See Canyon apple season usually begins in August and runs through December. You can find many types of apples from heirloom to brand-new varieties. Gravensteins (my favorite apple for pies), blondies and Mollie’s delicious ripen first in August and the Arkansas black and pink ladies can hang on through December.

With the progressively shorter days of fall and the holidays just around the corner, it’s become a family tradition to drive up See Canyon Road and visit the rustic apple farms that stretch along the creek through the magnificent canyon.

This week’s forecast

A historic snowstorm slammed into the Northeast on Saturday with between 6 and 12 inches of snow from northern Maryland to eastern Maine.

At the same time, temperatures throughout San Luis Obispo County, including the beaches, reached the low to high 80s.

A 1,029-millibar high over the Great Basin will produce gusty northeasterly (offshore) winds this morning. These winds will produce another spectacular fall day throughout the Central Coast with 80-degree readings everywhere.

Oktoberfest in Los Osos/Baywood Park should see temperatures reach the low 80s during the late morning hours, before the onshore winds cool things during the afternoon. A 6-foot high tide is expected about 1 p.m. in the back bay.

Minimum temperatures tonight will be similar or slightly warmer than Saturday night, generally in the 40s and low 50s.

A dry cold front will pass over our area Monday afternoon, followed by strong to gale-force (25 to 38 mph) northwesterly winds along the coastline and the return of coastal low clouds. This condition will produce cooler temperatures across all locations into Tuesday.

Another dry air mass will migrate across the state and bring another round of cool minimum temperatures and clear skies Wednesday through Thursday, with maximums in the mid-70s.

A strong 1,037-millibar eastern Pacific High will keep the storm track over the Pacific Northwest on Friday through Saturday. This condition will continue to produce dry and clear weather.

However, it will also give moderate gale to fresh gale (32 to 46 mph) north to northwesterly winds along the coast later Thursday through Saturday.

A weaken and battered cold front may produce some light showers Nov. 6.

Surf and sea report

Arriving from the Northwest, today’s 3- to 5-foot northwesterly (300-degree deep-water) swell (with an 8- to 12-second period) will continue at this height and period through Monday morning.

Increasing northwesterly winds will generate a 4- to 6-foot northwesterly (310-degree deep-water) sea and swell (with a 4- to 11-second period) Monday afternoon, further building to 8 to 10 feet (with a 7- to 17-second period) Tuesday.

This northwesterly sea and swell will decrease to 6 to 8 feet Wednesday, further lowering to 4 to 6 feet (with an 8- to 12-second period) Thursday.

Moderate gale to fresh gale (32 to 46 mph) north to northwesterly winds will generate an 8- to 10-foot northwesterly (300-degree deep-water) sea and swell (with a 5- to 11-second period) Friday through Saturday.

Reduce power outages

To significantly reduce power outages, PG&E reminds customers to follow these important safety tips for metallic balloons:

Use caution and avoid celebrating with metallic balloons near electric lines.

Make sure helium-filled metallic balloons are securely tied to a weight that is heavy enough to prevent them from floating away. Never remove the weight. Never release them outside.

Never try to retrieve any type of balloon, kite or toy that becomes caught in a power line. Leave it alone and immediately call PG&E at 800-743-5000.

Never go near a power line that has fallen to the ground or is dangling in the air. Always assume downed lines are live. Immediately call 911 to alert police and fire departments.

John Lindsey is a media relations representative for PG&E. He is also a local weather expert and has lived a­long the Central Coast for nearly 25 years. To subscribe to his daily weather forecast or ask him a question, email