Climate change refers to long-term shifts in temperatures and weather patterns. These shifts may be natural, such as through variations in the solar cycle.
UN
Climate change describes a change in the average conditions — such as temperature and rainfall — in a region over a long period of time. NASA scientists have observed Earth’s surface is warming, and many of the warmest years on record have happened in the past 20 years.
NASA - short answer
Weather describes the conditions outside right now in a specific place. For example, if you see that it’s raining outside right now, that’s a way to describe today’s weather. Rain, snow, wind, hurricanes, tornadoes — these are all weather events.
Climate, on the other hand, is more than just one or two rainy days. Climate describes the weather conditions that are expected in a region at a particular time of year.
Is it usually rainy or usually dry? Is it typically hot or typically cold? A region’s climate is determined by observing its weather over a period of many years—generally 30 years or more.
So, for example, one or two weeks of rainy
weather wouldn’t change the fact that Phoenix typically has a dry, desert
climate. Even though it’s rainy right now, we still expect Phoenix to be dry because that's what is usually the case.
Want to know more about the difference between weather and climate? Take a look at this video!
What Is Climate Change?
Alaska's Muir glacier in August 1941 and August 2004. Significant changes occurred in the 63 years between these two photos. Credit: USGS
Climate change describes a change in the average conditions — such as temperature and rainfall — in a region over a long period of time. For example, 20,000 years ago, much of the United States was covered in glaciers. In the United States today, we have a warmer climate and fewer glaciers.
Global climate change refers to the average long-term changes over the entire Earth. These include warming temperatures and changes in precipitation, as well as the effects of Earth’s warming, such as:
- Rising sea levels
- Shrinking mountain glaciers
- Ice melting at a faster rate than usual in Greenland, Antarctica and the Arctic
- Changes in flower and plant blooming times.
Earth’s climate has constantly been changing — even long before humans came into the picture. However, scientists have observed unusual changes recently. For example, Earth’s average temperature has been increasing much more quickly than they would expect over the past 150 years.
NASA - Longer Answer
I searched specifically for how to differentiate weather and climate and never got better than weather covers a short period of time and climate a long period of time. Personally - I like to use 3 months, year on year: "How do these three months compare to the same three months last year and the year before and the decade before and the century before, etc."