By Reginald Stanley. Posted January 1, 2020, 9:30 PM.

The decade of 2010 through 2019 has come and passed, and we at WeatherCurrents felt it was appropriate to summarize and review notable weather events and station additions that have taken place in that time across the region.

WeatherCurrents' longest-running station, located in south Temecula, reached its 20 year mark in August 2019. WeatherCurrents' stations in Hemet and Murrieta both went online four years later, in 2003. By 2010, WeatherCurrents had expanded to over twelve active weather stations across the region. Between 2010 and 2019, stations had gradually expanded further, and to new areas with noticeably different weather to the Inland Empire. By the end of 2019, WeatherCurrents maintained 17 active weather stations in Southern California. In addition to these stations, WeatherCurrents would like to thank our long-time contributors from the region including Jim Sappington from Temecula Valley's Wine Country, who has been contributing his storm totals to WeatherCurrents since at least 2004. In east San Jacinto, Monty Parrott contributed since at least 2007 through early 2018, and contributor Peter Michas of east Highland since 2012. More recently, Don Kramer of Yucaipa has also been submitting storm totals frequently since January 2018. WeatherCurrents thanks not only our contributors, but also the hosts of each and every station in the WeatherCurrents network, whom all maintain and care for all parts of the weather network.

In Southern California, 2010 began in the midst of a moderate-strength El Nino event. A significant stormy stretch occurred from January 17 through January 22. A 7.2 magnitude earthquake centered south of Mexicali, Mexico, was widely felt across the region on April 4, 2010. This was followed by an unusually cool Spring and Summer in the region, ended by a significant heat wave in late September. In December, one of the wettest stretches in recorded Southern California history brought continuous heavy rain from the 17th through the 23rd. While the record December rains remained limited to that month, the 2010-11 water year still ended as one of the wettest of the decade across the region. A particularly cold winter storm in late February 2011 made for picturesque wintry landscapes throughout Southern California, as snow fell to relatively low elevations. A cool Spring and mild Summer, similar to that of 2010, took place again in 2011. WeatherCurrents also added its most distant weather station to-date, Simi Valley, in 2011. Both 2010 and 2011 would remain the two coolest years of the decade, by a significant margin.

The year 2012 started out warm and dry, a pattern that would become familiar through most of the year. However, one cold storm managed to briefly buck the trend in March, resulting in hail, graupel and snow above 2000 feet during the storm. Two months later, a solar eclipse was visible on May 20. Summer thunderstorms also occurred, amid a hot August in the region, followed by inland residents reporting a foul odor which was later determined to be originating from blowing dust near the Salton Sea, which was high in sulfur content. Summer 2013 featured several abnormal temperature fluctuations from June through September, starting warmer than normal until turning much milder in late July. Mild weather continued until temperatures suddenly ramped up again in mid-August, peaking high above normal in early September, before cooling again later that month. Fall 2013 featured a number of mostly weak storms, followed by frequent incursions of strong high pressure as winter began. This set the stage for a very dry 2013-14 water year across all of Southern California, as 2014 started unusually warm and dry - a trend which dominated virtually the entire year. At the end of February 2014, the only significant storm of the rainy season occurred. Worsening drought conditions, above-average temperatures and numerous Santa Ana Wind events were commonplace in 2014.

A pleasant surprise happened for the inland valleys in late December 2014, however. A cold winter storm originating from the Gulf of Alaska interacted with cold offshore winds late one night, culminating in the early morning hours of December 31st, 2014 - producing significant snow as low as 1000 feet above sea level across the region. It marked the most significant, widespread low elevation snow event for the Inland Empire since November 2004. Despite this, the year 2014 ended with most WeatherCurrents stations reporting their warmest year of the decade. Warm, dry weather returned in early 2015, continuing the pattern from 2013-14. However, beginning in April 2015, above-average temperatures in the region began to gradually regress, with cool late-season storms occurring in May - resulting in an abnormal temperature pattern during Spring 2015. Summer 2015 was characterized by a highly active monsoon season, punctuated by record rains in July as a result of remnants of former Hurricane Dolores. Warm temperatures continued, however, eventually resulting in a very warm October. A powerful offshore wind event blasted the region in late December.

In early 2016, a strong El Nino had established itself in the equatorial Pacific - an event typically associated with above-average precipitation in Southern California. However, this was not occurring in 2015-16. Drought conditions remained amid below-average seasonal rainfall to-date, which had become apparent during a very warm, dry February in 2016. The 2015-16 water year ended as the fifth consecutive below-average rainy season in Southern California, with the strong El Nino having failed to meet expectations for the first time since at least 1950. The summer of 2016 was warm but not particularly remarkable, with the most severe heat wave occurring back in June. The region finally began seeing relief from drought late in 2016, as multiple wet storms gave a healthy start to what would be the region's first above-average rainy season since 2011. Wet weather intensified in January 2017, resulting in the wettest January in the region since 2010. By March, all active WeatherCurrents stations had exceeded their seasonal rainfall averages. A dry March and April hampered an otherwise wet rainy season in 2016-17, however it still ended above-average across the region. July, August and September of 2017 featured active thunderstorms in Southern California, peaking during a heat wave in late August.

Fall 2017 was marked by persistent above-average temperatures, heat waves in October and November, severe Santa Ana Wind events in December which fanned multiple wildfires, and an overall absence of storm activity in the region. The months of October, November and December of 2017 all featured very little to no rainfall in the region. The only significant storm of the 2017-18 water year brought heavy rain to the region in mid-January. Colder, more seasonable weather did not arrive until late February in Southern California. Weak storms in March 2018 brought a sort of faux March Miracle, and did little to alleviate a meager rainy season. The 2017-18 water year was one of two rainy season low points during the decade, with the other being 2013-14, and was one of the driest on record in much of Southern California. A heat wave featuring record-breaking temperatures engulfed the region in early July 2018. That month ended as one of the warmest Julys in recent history. Exacerbated by drought conditions and high temperatures, the Holy Fire burned thousands of acres in the Santa Ana Mountains in August.

In October, remnants of former Hurricane Sergio interacted with low pressure to bring modest precipitation to the region. The 2018-19 water year got off to a healthy start in Fall, courtesy of several wet storms in November and December. These rains continued into January 2019, and intensified in February along with colder temperatures in the region. A major storm brought record-breaking daily rainfall to much of Southern California on February 14th, 2019. Video footage of heavy creek flows in Temecula Valley's Wine Country was captured by contributor Jim Sappington during the storm. A notable instance of rain mixed with snow occurred in parts of western Riverside County, during a cold storm on the 21st. Ultimately, February 2019 became one of the coldest and wettest months of the decade in the region. Bountiful rains resulted in the third and final above-average rainy season of the decade, as well as producing spectacular wildflower blooms across the state. Additional cold, late-season storms were still affecting the region in late May. Aside from two moderate heat waves in June and July, the summer of 2019 was generally quiet across the region. 2019 ended as one of the few relatively mild years of the decade, with only 2010 and 2011 being cooler.