I have never heard the term "cold snap" in all of my years living in the US

I've hear"Cold snap" is a thing -- it might be a regionalism. I've never heard of "cold wave." Probably "cold front" or "cold spell" is better.

Duo. is too forgiving when it comes to mistakes made in Hebrew. On the exercise 'Type what you hear' I typed this below:

גם הקור הזה לא עוזב אותנו.

It's not what the recording said. It said 'gal' not 'gam.' I could understand if I got it correct if I added an aleph or an hey but I wrote a totally different word that changes the meaning of the sentence.

In English sometimes I'll use the word 'a' when it should be 'an' and I get the whole thing wrong according to Duo. It's just a minor grammer mistake that doesn't change the meaing of the sentence.

that's exactly what I wrote but it's poor English!!

I grew up in Cincinnati Ohio so my regional influence would explain a cold snap as a sudden significant drop in daytime temperatures. A cold wave would be a predicted cold temperatures over an extended timeframe.

A cold front is different and describes a meteorological phenomenon that is beyond my understanding to explain.

It's not a cold snap (in the US) and wave only applies to heat, ie heat wave. In the US the most common phrase is "cold front." I have never heard of cold snap ever before in my life.