This paper investigates the spatiotemporal variations of the Surface Urban Heat
Island (SUHI) computed as the difference of urban and rural land surface
temperatures for the three major cities of Argentina: Buenos Aires, Rosario, and
Cordoba. Satellite-based data of 1 km x 1 km resolution available through the Global
Surface UHI Explorer were used to estimate mean and maximum values, trends
and percentage of each urban area with positive/negative intensities of SUHI for
the period 2003-2017. Results indicate that, on average the nocturnal urban surface
temperature is higher than the rural one (positive SUHI) for the annual, winter
and summer mean for the three cities. The greatest contrast corresponds to Buenos
Aires, where the maximum SUHI magnitude is +2 ◦ C in summer and the minimum
is +1,5 ◦ C in winter. Both Rosario and Cordoba exhibit a difference in magnitude
between summer and winter of only 0,1 ◦ C. The percentage of the area of each city
with nocturnal surface temperatures greater than the rural ones is on average, 93 %
for Buenos Aires, 97 % for Rosario and 89 % for Cordoba. During daytime, in some
cases the SUHI intensity is negative generating a cold island. This effect is observed
in the three cities during the cold season and in Rosario and Cordoba for the annual
mean. In Buenos Aires, that hosts more than 30 % of the total population of the
country, there is a significant positive trend in the daytime mean and maximum
SUHI intensity. The comparison between the Buenos Aires’ SUHI and canopy UHI
(derived from standard air temperature measurements) shows positive intensities
during night-time in both cases, although the mean annual and summer SUHI are
warmer than the UHI in +0,3 ◦ C and +0,6 ◦ C, respectively. Additionally, there is a
trend towards warmer daytime intensities of both types of heat islands.