Our Friend ENSO

City Fruit is a seasonally affected organization.  Hopefully this doesn’t come as a surprise!  The majority of our purpose and mission, harvesting, depends heavily on climate.  Unripe fruit serves little purpose in our community, so our summer activity/productivity is determined by winter and spring weather.  

In recent history, we’ve had both slim pickings and a bumper crop, referring to 2022 and 2023 respectively.  Last year in particular, we had an unprecedented number of harvests, yielding 44,829 pounds of fruit over the course of four months!  The preceding year, 2022, was far less productive in quantitative terms.  We harvested notably fewer pounds of plums, by roughly 6,000 pounds.  Why?

Our friend ENSO: El Niño-Southern Oscillation.  ENSO refers not only to El Niño, but also La Niña: two phases composing the climate pattern that dictates (among other things) Pacific Northwest fruit production. 

Not being a climatologist myself, I’ll put this in layman’s terms: El Niño indicates warmer than usual temperatures in the tropical Pacific; La Niña means cooler than normal.  This is due to ocean surface temperature and trade winds along the equator.  These winds can weaken and even reverse course during El Niño months, generating more rainfall. 

Above: El Niño patterns warming the northern continental US and Canada, courtesy of the National Oceanic and Atmospheric Administration (NOAA)

During La Niña, winds pick up and precipitation can lessen.  The exception is Indonesia, where the effects of ENSO are opposite of those in the Northern Hemisphere. 

Above: La Niña patterns causing heavier rainfall in the Pacific Northwest, courtesy of NOAA

Neutral conditions are the alternative to the pendulum of Niño/Niña, which present (as one might guess) with the absence of the characteristic atmospheric extremes.

What does this mean for the Pacific Northwest?  Recollect December of 2023: the warmest December on record, with temperatures averaging over 45 degrees; El Niño in action.  Warmer and drier winters indicate the effects of El Niño in Washington, and can be indicative of future drought.  Regardless of our persistent drizzle resident identity, lower rainfall can have a negative impact on agriculture, and specifically fruit production.  Climate is only one in a multitude of factors affecting fruit tree production (soil health, pollination, age, pollution), but it’s a heavily weighted factor.  

ENSO patterns are consistent, but the effects aren’t always so predictable, as the contrast of City Fruit’s 2022 and 2023 harvests demonstrate.  While 2022 was scant in poundage, 2023 proved bountiful, and these were both technically effects of a triple-dip La Niña (three consecutive years of these conditions: 2020-2023).

Confused?  There’s more!  Scientists are not quite sure why we endured three years of La Niña conditions without the somewhat requisite preceding strength of El Niño.

Any experienced human probably isn’t counting on the weather.  Like in the course of history, change is the only constant.  Seattle Metropolitan Magazine recently featured a piece written by Justin Shaw of the Seattle Weather Blog, who wisely noted “the odds don’t tell the full story… playing the odds isn’t a foolproof strategy. Mother Nature is fickle, and just because the dice are weighted one way doesn’t mean that’s how they’ll always fall.”

All this to say, you could experience an excess of fruit this summer.  If you find yourself with more than enough, give us a holler.