El Niño 2015 set a new heat record on Wednesday, putting it on track to become the strongest El Niño ever seen in history.

The Weather Network reports that El Niño has been very unusual this year. It has already set a new record in weekly measurements of temperatures in the central Pacific Ocean, which are now at 3.0 degrees Celsius above normal.

Records show that, within the last 25 years, temperature anomalies in other regions of the Pacific have only reached that temperature or higher between 1997 and 1998. El Niño saw a peak from May 1997 to February 1998 and from April 1998 to June 1998, when it reached 4.6 degrees Celsius above normal.

"While a short-term (daily or weekly) number might be striking, it shouldn't be used as an indicator of El Niño strength unless it is carefully placed into a larger context," said Michelle L'Heureux, a meterologist at the NOAA Climate Prediction Center.

Yet, El Niño has been rising significantly since the beginning of September, and it could continue to rise with the overall weather forecast for the year.

It is hard to tell how the season will play out since the pattern fluctuates daily.

"It's certainly impressive that the weekly got to 3 degrees Celsius," Tom Di Liberto, another meteorologist at NOAA's Climate Prediction Center, told Mashable. "But we've been trying to say that we don't know if this is a blip or a longer-term pattern. Just because we had a week at this level doesn't necessarily mean that this is the strength of this El Niño."

Meteorologists usually measure El Niño by a three-month average temperature index. This longer-term index shows that this year El Niño could set a new record or could fall short.

Check out this Twitter photo of this year's weekly El Nino recording compared with those in 1982 and 1987.

Related