Last month's average temperatures across the world were the fourth warmest for April since records began in 1950.
The Copernicus Climate Change Service (C3S) found temperatures were above average over south-west Europe last month, with Spain and Portugal recording their highest April temperatures.
The C3S, which is part of the European Centre for Medium-Range Weather Forecasts and is funded by the European Commission, publishes monthly climate bulletins on changes observed in the weather.
All findings are based on computer-generated analyses using billions of measurements from satellites, ships, aircraft and weather stations around the world.
The latest data, published on Monday, covers April and despite some areas experiencing record highs, it also noted colder-than-average temperatures in a band stretching from the UK to south-east Europe.
It said temperatures for the month were much warmer than average in parts of Africa, part of Central Asia surrounding the Caspian Sea, in South-east Asia, Japan and Canada.
In contrast, it was colder than average in Alaska, Mongolia, the Arabian Gulf, India and Australia.
"April saw exceptionally warm temperatures in Spain and Portugal, which were accompanied by extremely dry conditions," said Samantha Burgess, deputy director of C3S.
"In addition to the southern European heatwave, above-average temperatures were observed over the equatorial eastern Pacific, which is an early sign for a potential transition to El Nino conditions often leading to warmer global temperatures."
Exceptionally dry conditions were experienced in the Iberian Peninsula, the Southern Alps and parts of Mediterranean France, the report said.
A number of ski resorts were forced to close due to lack of snow.
Other drier-than-average regions included north-western Scandinavia, the Baltic countries and much of western Russia.
Last month was wetter than the average April in a large west-to-east region from Ireland, the UK and France, across central Europe to Italy, the Balkans and the Black Sea.
Beyond Europe, this April was drier than average over large parts of the USA, in western Russia and in parts of South-east Asia.
Other drier-than-average regions included the Horn of Africa, most of southern Africa, Argentina and parts of Brazil.
Wetter-than-average conditions were recorded in south-eastern USA, regions of East Asia, north-western Australia and Tanzania.
Below-average sea ice concentrations prevailed in most sectors of the Arctic Ocean, the report said.
Last month C3S published its sixth annual European State of the Climate report, which revealed that low rainfall and high temperatures had led to widespread drought across the continent.
It warned Europe would soon recognise the cost of climate change as drought conditions are expected to affect food production significantly this year.
