Armstrong Redwoods SNR illustrates the remarkable coastal microclimates of Northern California. Winter temperatures are moderate and rain brings life to the many plants and ferns that carpet the forest floor. The rainfall in Armstrong Redwoods averages 55 inches per year and the trees are often shrouded in a mystical fog that helps to maintain the moist conditions needed for the redwoods to survive.
In spring, wildflowers are prolific and temperatures are mild and the fog is less frequent. Summer rolls in and with it morning fog that blankets the grove and cools the air. Afternoon temperatures warm the forest floor and in the upper hills of Austin Creek temperatures can climb to over 100 degrees.