All months in 2014 have been warmer, and four months were more than 1ºC warmer, than the 1981-2010 average, Friends of the Earth Scotland said.
Spring this year has been the warmest since records began, with a mean temperature of 7.69ºC.
April was the fourth warmest ever recorded, with a mean temperature of 7.9ºC, while June was fourth equal for the position of warmest ever, with a mean temperature of 12.9ºC.
The group's analysis of Met Office data also found that February was the fifth wettest ever recorded.
Friends of the Earth Scotland said Scots should heed the warnings the weather is giving us, and it called for more action to tackle climate change.
Director Dr Richard Dixon said: "Scotland's weather is showing a very clear long-term trend of increasing temperatures, just as climate change scientists predict.
"Climate change brings not just increasing global temperatures but increasingly unpredictable weather. Scotland is caught between the changing influences of disappearing Arctic ice, the shifting jet stream and a weakening Gulf Stream. The consequences for us are more extreme weather."
He added: "We should heed the warnings the weather is giving us because things will get much worse if the world continues to pump greenhouse gases into the atmosphere at the current rate.
"The world's big polluters are getting more serious about reducing climate change emissions but they need to start agreeing tough new targets."
May 2014 was the planet's warmest May ever recorded, the charity added.