The Amphibians and Reptiles of Sinaloa, Mexico - Smithsonian ...

46 UNIVERSITY OF KANSAS PUBLS., MUS. NAT. HIST.
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• • AHOME
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18 20 22 24 26 28 30
32
MEAN MONTHLY TEMPERATURE (• C.)
Fic. 2. Temperature-moisture climograph comparing a lowland (Ahome) and
highland (Choix) locality in northern Sinaloa, Mexico. Each point represents
a month, proceeding counter-clockwise from January (J),
July and August, and decrease from 38.6°C at Ahome to 29.5°C at
Mazatlan. In the highlands the warmest months are May and June,
and the temperatures decrease southward from 39.1°C in June at
Choix to 34.9°C in May at Panuco. The highest daily temperatures
decrease from north to south and usually are recorded in July,
September, or October. The lowest mean monthly temperatures in
the lowlands was 8.1°C for January at Guamuchil, The lowest lowland
temperature recorded, —1.1°C, was also in January at Guamuchil.
In the highlands the lowest mean monthly temperature
was recorded from central Sinaloa, 6.2°C at Badiraguato. The
lowest temperature reported in the state was at Badiraguato in
January when the thermometer dipped to — 2.5°C.
Temperatures fluctuate between monthly and daily extremes in
northern Sinaloa but remain nearly constant in the southern part of
the state. For brief periods during the dry season, temperatures in
the north may show a daily fluctuation of 20°C. During the months
of June to November the daily fluctuations rarely exceed 15°C and
commonly remain near 11°C. Stability in temperature is characteristic
of the southern limits of the state; at Mazadan the greatest
fluctuation is 5.1°C in April, and at Panuco the greatest monthly
fluctuation is 15.2°C in March. Temperatures are almost continu-