Answer
5.5 degrees
Work Step by Step
January: -19.3
September: 27.0
October: 8.8
Average: $\frac{-19.3+27.0+8.8}{3}=\frac{27.0-19.3+8.8}{3}=\frac{7.7+8.8}{3}=\frac{16.5}{3}=5.5$ degrees Fahrenheit
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