The 1630s were probably not as bad as 1608; Champlain found bearing ice on the edges of Lake Superior in
Spring water temperatures have been reconstructed for Chesapeake Bay based on crustacea mineral ratios. Temperatures were high in the first quarter of the 17th century (higher, in fact, than in the Medieval Warm Period), but then declined, reaching a low in the mid-18th century. In our period, we have 16.6 (1638), 8.97 (1642) and 10.74 oC (1646). The most recent value was 12.5 oC (1995) (Cronin)
In tropical America, the seasons are wet or dry, not hot or cold. The seasonal variation in rainfall is correlated with the seasonal movement of the Inter-Tropical Convergence Zone (ITCZ), northward in the NH summer and southward in the NH winter. In NH summer, it's over northern Venezuela, and that's the rainy season.
In northwest Yucatan and in Venezuela, the general period 1500-1800 was marked by drier conditions, usually attributed to a 'southward displacement of the ITCZ and hence reduced trade wind moisture supply to the Caribbean during the summer.' However, at Lago Verde at the Isthmus of Mexico, a 'particularly wet area,' this change was apparently not enough to create a moisture deficiency. Indeed, 1600-1650 seems to have been a very good half-century for the tropical forest growth there, suggesting that the dry season was shorter than usual (Lozano-Garcia; Peterson).
On the other hand, in northeast Peru, the LIA was about 10-20% wetter than the 20th century, with the late 16th and the 17th centuries being the wettest period (Reuter).
In the Venezuelan Andes, there were glacial advances in 1180-1350, 1450-1590, 1640-1730, and 1800-1820. (Polissar). However, in the Cariaco Basin (offshore Venezuela), sea surface temperatures were higher in the 17th century than in the 20th (Reuter).
In central Chile, the 1630s were a bit drier than normal (LambCPFF 638), which would have made rivers easier to ford, but also reduced crop yield.
Information on African conditions is pretty limited. Grove (38) says that southern Africa experienced 'sudden warming from 1500 to 1675.' In the Makapansgat Valley of South Africa, per speleotherm data, temperatures seem to have been slightly depressed (relative to 1961-1990 base) during the period ~1320-~1750 (Tyson fig. 3). As best I can tell, in the 1630s we were edging up from a low (about 0.5oC below the base) reached around 1600.
In equatorial Africa, the 17th century was marked by droughts in the west and center, and (at least after 1625) wet conditions from Lake Victoria east (Russell; Verschuren). It has been suggested that megadroughts in West Africa were associated with anomalously strong Atlantic trade winds (Overpeck), which would have facilitated colonization of the Americas. The area of Timbuktu was punished by famines due to drought (in 1617-1743) and by great floods (in 1640-1672 and 1703-1738), often in the same year (LambCHMW 226).
Monsoons are seasonal changes in prevailing wind direction. The Monsoon is essentially the Mother of All Sea Breezes (and Land Breezes). Water warms and cools more slowly than land. It is common for coasts to experience a sea breeze (wind blowing from the sea toward the land) during the morning, the air over the land warming first. Then, in the evening, there is a land breeze in the reverse direction, the air over the sea cooling last.
In a monsoon, this happens on a giant scale, and the 'breeze' persists for several months. The summer monsoon, being a giant sea breeze, results in high humidity. And the winter monsoon, being a giant land breeze, brings dry conditions. (Unless the winds sweep over intervening water, such as the Bay of Bengal, before they reach you.)
In the Indian Ocean, there is a summer monsoon, with winds from the southwest, and a winter monsoon, with winds from the northeast. The exact dates of arrival and departure of the monsoons varies depending on exactly where you are located.
There is absolutely no doubt that there were monsoons in the Indian Ocean and the western Pacific Ocean before the Ring of Fire; in fact, trade and agriculture depended upon them.
The failure of the monsoon can result in a megadrought, with substantial loss of life.
A network of tree ring chronologies has been used to reconstruction monsoon conditions for Sino-Indian Asia; Figures 5A-5D show the 'Palmer Drought Severity Index' (red dry, blue wet) for the region for the years 1630-1641 (NOAA/MADAgrid). Don't fret about the particular years, since the RoF will scramble that, but note the degree of variation from year to year.
Figures 5A-5D
In the Pacific, there is a alternation between two climate patterns, 'El Nino' and 'La Nina' over a period of three to seven years. These opposite states may persist for just a few months or for as much as two years.
In an 'El Nino' state, there is (by definition) a warming of at least 0.5oC of the surface temperature in the east-central tropical Pacific Ocean. This weakens the trade winds of the South Pacific, and causes drought in the western Pacific and rainfall in the eastern Pacific. Off the coast of Peru, the upwelling of cold water is inhibited, and this results in fish kills. Winters in western South America tend to be much warmer and wetter than usual. The same is true, to a lesser degree, on the Pacific Coast of Central America, Mexico, and southern and central California. However, in the northwestern United States and western Canada, winters are warmer and drier.
We know from documentary evidence (mostly from Peru) that there was a very strong event in 1578 (comparable in strength to the 1982-3 event), and since then, strong ones in 1607, 1614, 1618, 1619, and 1624 (comparable to the 1972-3 event). If climate follows the old time line path, there will be strong ones in 1634-35 and 1640-41, and a moderately strong one in 1647 (Arteaga; Quinn).
There's also the IPO, which flips every 15-30 years. In a positive IPO, India experiences a weak monsoon and associated drought, and the American West Coast is wet.
