The findings are in an annual report by the UN weather agency and the UK's Met Office which gives regional predictions for temperatures and rain.
It predicts annual global mean near-surface temperatures will range between 1.3C and 1.9C above the 1850-1900 pre-industrial period.
"There's very clear evidence that the climate is warming and that the global average temperature is continuing to rise," Melissa Seabrook, a research scientist at the UK Met Office, said on Thursday.
In the 2015 Paris Agreement, governments promised to try to prevent the average global temperature rise from exceeding 1.5C above pre-industrial levels - above which severe climate events were seen growing in intensity.
The report said it was very likely the global mean near-surface temperature would temporarily exceed 1.5C above the 1850-1900 average levels for at least one year between 2026 and 2030.
It also predicts there will be one year between 2026 and 2030 that average global temperatures will exceed the warmest year on record, 2024, when they surpassed 1.5C above the pre-industrial era for the first time.
Temporarily crossing the 1.5C threshold does not mean the Paris Agreement had failed, as it referred to a long-term average over 20 years rather than a single year's exceedance, Seabrook said, while noting that as the world gets closer to that threshold, it was increasingly likely to pass it more often.
"The science is very clear that the window to keeping the global average temperature to 1.5 degrees is closing rapidly," Seabrook added.
Arctic winter temperatures in the northern hemisphere over the next five years are projected to rise at more than 3-1/2 times the global average, reaching around 2.8C above the 1991–2020 baseline, according to the report.
Arctic sea-ice is expected to melt in the month of March over the next half decade in the Barents Sea, Bering Sea and Sea of Okhotsk.
Arctic warming could also disrupt weather systems and prompt more severe weather events, especially in northern parts of the world, Seabrook said.
Wetter weather in the northern hemisphere over the next five winters is also predicted, as well as wet periods in northern Europe, Alaska, Siberia and the Sahel during May-September, while contrastingly dry weather is forecast for this season in the Amazon.
A strong El Nino is also predicted for winter this year, which could persist into 2027, driving up global temperatures to potential record-breaking levels due to the heating of the Pacific Ocean, Seabrook said.
El Nino is a periodic warming of sea surface temperatures in the central and eastern Pacific Ocean, which typically lasts between nine and 12 months.
9°C