Climate Change Chart of Los Angeles, USA

Overview of climate changes

Changes in sunshine duration

Mean daily sunshine duration, averaged across calendar months, had a difference of -0.48 hours/day compared with the earlier period. This unweighted monthly average summarizes the comparison without implying that daily sunshine changed by the same amount throughout the year. The largest monthly decrease occurred in May, with a difference of -1.27 hours/day; by contrast, the largest monthly increase was in February, with a difference of +0.22 hours/day. These are the extrema among the supplied monthly differences, not a description of every month.

Changes in rainfall

Mean daily rainfall, averaged across calendar months, had a difference of -0.02 mm/day. This small aggregate decrease does not mean rainfall fell in every month, and the measure is a daily mean rather than a monthly total. The largest monthly decrease was in February, a difference of -1.26 mm/day, while January recorded the largest increase, a difference of +0.63 mm/day. These contrasting monthly changes show why the near-unchanged average across months does not describe each month’s difference.

Temperature changes

Averaged across calendar months, monthly mean temperature shows a difference of +1.28 °C compared with the earlier reference period; this is an unweighted mean of monthly means, not a day-weighted annual average or a measure of daytime maximum temperatures. The largest monthly increase in mean temperature occurred in January, with a difference of +2.61 °C. This identifies the strongest increase among the supplied monthly differences, rather than implying the same change in every month.

Changes in snowfall

Averaged across calendar months, mean daily snowfall had a difference of 0.00 mm/day at the displayed precision. That rounded aggregate does not establish that snowfall was absent or unchanged beyond this precision. Monthly differences were mixed: the largest decrease was in January, with a difference of -0.05 mm/day, while the largest increase was in February, with a difference of +0.02 mm/day. These daily-mean amounts are not monthly snowfall totals.