(a) Plot a combined rainfall and temperature graph for Station X (b) Calculate the (i) annual temperature range (ii) mean annual temperature for the station...

Answer Details

(a) Combined rainfall and temperature graph for Station X

The monthly figures for the station are set out below. Temperature is plotted on the left-hand vertical axis as points joined by a smooth curve; rainfall is plotted on the right-hand vertical axis as vertical bars, one for each month.

Month	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Temp (\(^{\circ}\)C)	21	21	20	17	15	12	12	13	14	18	18	20
Rainfall (mm)	5	8	20	45	80	110	105	90	60	35	15	8

The completed climate graph is shown below.

(b) Calculations

(i) Annual temperature range = temperature of the hottest month minus temperature of the coldest month:

\[ \text{Range} = 21^{\circ}\text{C} - 12^{\circ}\text{C} = 9^{\circ}\text{C}. \]

(ii) Mean annual temperature = sum of the twelve monthly temperatures divided by 12:

\[ \bar{T} = \frac{21+21+20+17+15+12+12+13+14+18+18+20}{12} = \frac{201}{12} = 16.8^{\circ}\text{C}. \]

(c) Climatic type

The station has a small annual temperature range (9\(^{\circ}\)C) with warmth throughout the year, and its highest temperatures (Dec-Feb) fall in the driest months while the heaviest rain (Jun-Aug) comes in the cooler months. Hot, dry summers combined with mild, wet winters identify the station as a Mediterranean (warm temperate western margin) climate. Because the hot dry season occurs in December-February, the station lies in the Southern Hemisphere.