estival vs oppressive

estival

adj
  • Coming forth in the summer. 

  • Of or relating to summer. 

oppressive

adj
  • Hot and humid of the weather. 

  • Tyrannical or exercising unjust power. 

  • Burdensome or difficult to bear. 

  • Weighing heavily on the spirit; intense, or overwhelming 

How often have the words estival and oppressive occurred in a corpus of books? (source: Google Ngram Viewer )