Today, The New York Times publishes an interactive chart showing detailed temperature and precipitation patterns for 1,801 American cities and 1,334 other locations around the globe for 2015. More than 90 percent of the cities had a warmer-than-average year – local evidence of the fact that 2015 was the hottest year on record.
The interactive gives you an opportunity to explore an exceptional year in weather. It is based on a database compiled by Accuweather, a weather forecasting media company.
Here are highlights from the 2015 data, and a look at how the chart has evolved over the past 37 previous years.
For cities in the Northern Hemisphere, the chart curves upward, with temperatures peaking in the summer months. New York, shown below, has a typical pattern, with an atypically cold February and a strangely warm December. The city recorded record high temperatures on five different days that month.
In the Southern Hemisphere, the weather pattern is inverted. Here’s Melbourne, which had a cool winter and an uncharacteristically hot summer, with highs breaking 100 degrees eight times, including one day at 105 degrees, setting a new December high temperature record. It also suffered from extensive drought; rainfall was below average every month but July, including several historically dry months.
Closer to the equator, there’s not much variation in temperature at all, giving the chart a flat look. The daily high in Honolulu is almost always between 80 and 90 degrees. This year there were reports of frost during the winter and record high temperatures 25 times. And it was particularly wet in August and September.
In Antarctica, temperatures are literally off the charts.
Finally, some trivia. If this chart has a familiar look to print subscribers (bless you), it may be because we’ve been printing a version of it in our newspaper every year for at least the last 37 years. The version we’re publishing online today is the first time it’s been online.
The first appearance we could find was on Jan. 7, 1979, describing the 1978 year in weather. The chart is hand-drawn. Highs and lows are represented using the fever-line chart form.
Twelve years later, on Jan. 6, 1991, it changed slightly, removing the background and visually emphasizing unusual highs and lows.
Seven years later, our colleague Baden Copeland, a cartographer and manager who coordinates many of our print maps, changed the temperature chart to bars. It published on Jan. 4, 1998.
The design that readers are probably most familiar with was first published 15 years ago, on Jan. 7, 2001, when it appeared in color for the first time. It was also the first year that we produced versions of the chart for Boston and Washington.
Now, the chart is available online for more than 3,000 cities.