On good days in January it's clear and almost cool in Belize. The normally heavy tropical air thins to crystal and only an occasional puff of trade wind cloud mars the seamless blue Caribbean sky. Yellow-eyed blackbirds, their long tails jerking impatiently, strut like minor officials beneath the coconut palms and banana trees, and on rocks beside potholed roads piercing the low, mangrove jungle, sunbaked iguanas flick lazily at passing flies.

At irregular intervals during the month an ominous "norte" whirls in from the central Caribbean, fracturing the palm frond idyl with rain and unseasonable chill. The prevailing southeast trade winds shift sharply to the north, and thick clouds tumble inland over the jungle flatlands toward the mountainous Guatemalan border.

A norte normally lasts three days, but sometimes they come back to back. In late December and early January, a general run of nortes struck the mountains with unusual force, triggering monsoon rains. The khaki, bayou- wide Belize River rose nine feet at one point, flooding the 40-mile gravel road to the country's tiny moonscape capital of Belmopan. The New River, a narrow, eerily beautiful waterway flanked upstream with orchid-hung banyans and lush parasitical ferns, rose even higher. Here just south of the Yucatan border where it empties into Chetumal Bay, the impenetrable mangrove thickets along its winding channel remain bent outward on the curves, as if leaned on by some elephantine force.

For Belizeans, the menace and mystery of weather lie perpetually coiled offstage, another special effect in a movie-set country tailor-made for Indiana Jones. Sharks patrol the barrier reef offshore. Inland jungle swarms with 35 species of snake and a voracious insect called the wee wee ant. Overgrown Mayan ruins brood largely unexplored beside lagoons rife with crocodiles. Untraceable rivers appear as cliffside waterfalls, then vanish as mysteriously underground. A few months ago, someone spelunking in the southwestern mountains discovered the world's second largest cave chamber. "Dogs of War" was filmed in Belize. "The Mosquito Coast" will be.

First settled by 17th century pirates preying on Spanish treasure galleons, Belize has drowsed since in mosquito-bitten slumber, a hurricane- raked coast memorialized only by Aldous Huxley. In his 1934 book "Beyond the Mexique Bay," he wrote:

"If the world had any ends, [Belize] would certainly be one of them. It is not on the way from anywhere to anywhere else. It has no strategic value. It is all but uninhabited."

In the smoldering Central America of the 1980s, however, Belize has come of strategic age. Tiny as it is, its position at the foot of Mexico makes it a potentially unyielding domino, across whose notoriosly porous borders any major arms shipments from Cuba or Nicaragua would logically travel.

"Living in Belize is like living in Casablanca," said expatriate American Will Harmon one night over a Belikan beer in San Pedro.

"About three times a day, somebody comes up to you with a fantastic scheme of some kind for making a fortune. It may involve smuggling or drugs or timbering or Mayan artifacts or just development investment. But the figure is always the same: $2 million."

That endangered species, the soldier of fortune, still thrives in Belize. The country is peppered with tiny remote airstrips of mysterious origin. It is possible in a week's visit here to stumble, as some Americans did early this month, on the fresh but empty wreckage of a smuggler's light plane, its identification numbers erased, in the shallow waters of Corozal bay. Or be seriously invited in a bar, as another was, to parachute into Afghanistan later this year.

Yet Belizeans themselves -- descendants of English pirates, African mahogany cutters, Spanish-speaking mestizos from Yucatan, German-sp eaking Mennonites, Mayan Indians and seagoing Caribs -- are an improbably orderly lot, combining a British tolerance for personal eccentricity and private adventure with a preference for order and predictability in the public sphere.

Drug use, for example, is far less evident than in, say, Jamaica, though marijuana has been for years the number one Belizean cash crop. An estimated $100 million industry, it dwarfs the nation's $90 million in legitimate exports.

In a New Hampshire-sized country with only 150,000 people, the impact of that money, according an official in the U.S. Drug Enforcement Agency, makes drug trafficking "more significant in Belize than in any other country in Latin America." Residents here call it "America's real foreign aid program."

"Almost everyone you meet in this country is at least tangentially involved in the marijuana trade," said one. "Most never see the stuff. But they may rent a plane or an airstrip to someone. Or a truck. They may lease out some land or ignore someone's use of it. It's so widespread the U.S. is crazy to try to stop it. It would be cheaper for them just to buy it and burn it. Marijuana has turned a very poor Caribbean country into a very stable one."

That stability endures despite the Damoclean presence of the guerrilla war in neighboring Guatemala. "The Guats," as they're referred to here, have never relinquished their claim to Belize and threaten periodically to invade.

Britain's 1,500-man defense force in residence -- legacy of the country's century and a half as British Honduras -- contributes heavily to the national atmosphere of intrigue. At Belize International Airport, a garage- sized structure of mildewed concrete pregnant with safari clothes and expectation, a camouflaged machine gun bunker commands the runways, muscular commandos jog the approach roads and Harrier jump jets, cloaked in jungle olive and black, lie secreted behind barbed wire in corrugated compounds.

When the defense force included Ghurkas, rumors circulated among the stilted frame shanties of Belize City that the Ghurkas ate babies. The rumor was encouraged -- or at least not discouraged -- by the Brits, in hopes it would make its way across the border. Things have been relatively quiet since on the Guatemalan front.

The British are a perfect proxy here for U.S. interests, eyeballing border traffic in the name of Belizean defense, without the hegemonic taint of the Gringo puppeteer.

"We got no hassle with the Brits," said a onetime Belizean radical mellowed to political cynicism in his 30s. "If the U.S. had troops here, they'd be like a target, and there'd be trouble. But no one could rally anybody in Belize against the British. They have no perceived interest here except in keeping us free."

The U.S. presence, however, is beefing up in Belize in less visible ways. The Agency for International Development contingent hovers around 85, and the number of Peace Corps volunteers has ballooned from around 60 towards a reported target of 150. The Voice of America is installing a new transmitter on 217 acres near the Guatemalan border.

Then there is the unofficial U.S. presence: the marijuana trade. It is so heavy at times that in the town of Orange Walk, jumping off point to the northern jungle outback, more U.S. dollars circulate than Belizean. Dozens of Indians and mestizos walk in along the dusty trails to purchase new four-wheel-drive Chevy Broncos with $100 bills.

Today the dope trade appears somewhat in remission, due to stepped-up U.S. control efforts that recently helped jerk the gauzily left-of-center government of Belize rather dramatically to the right. Former Prime Minister George Price, an ascetic one-time seminarian who had dominated the country's politics for 30 years, was swept with his People's United Party from power last Dec. 15 in a political upset that stunned diplomatic observers in Belize City.

The opposition United Democratic Party, which had never won an election, claimed 21 of the country's 28 parliamentary seats. From the political circles of Belize City and Belmopan to the fishermen of Ambergris Key, Belizeans agree it was dope that did it.

Under pressure from the U.S. Drug Enforcement Agency to control his country's mushrooming marijuana production, Price in 1983 ordered a highly controversial -- and some say highly selective -- paraquat spraying that reportedly hit as many people as plants and left some of his allies' fields untouched.

"That man, he cares nothing for personal things. He lives in a room like a closet," said one fisherman in Corozal. "But his ministers were getting drug payoffs and for political reasons he turned a blind eye. He waited too long to do something about the marijuana, and when he finally came down on it, he made everybody mad and they turned him out."

Price remains widely revered even after his ouster. He is credited even by his few critics with everything from fathering Belizean independence to designing an impressive church-state educational system that has made literacy in this largely Catholic country virtually universal.

But he also made the Reagan administration nervous by periodically spicing his lifelong centrist tendencies with visits to Cuba's Fidel Castro or the Nicaraguan Sandinistas, and appointing two leftist ministers.

His successor, a 44-year-old junior college physics teacher named Manuel Esquivel, and his United Democratic Party, campaigned with "Stop Communism" slogans, and strongly espouse foreign investment and free enterprise capitalism.

Cynics say that means free enterprise marijuana. Others are less sure.

"I went to school with those fellows, but who knows what they're going to do," said one civil servant in Belmopan. Price and his People's United Party, she said, "have been in longer than some of them are old."

That was a jab at Derek Aikman, 25, the new minister of transport, education and youth, who defeated the 65-year-old Price. Aikman holds a degree in something called human resources management from Biscayne College in Miami, and managed the Belize office of Air Florida before that company went out of business.

Some say Aikman, a young man of polished presence and high ambition, is the manicured-for-media face of a new Belize emerging from the country's rag-tag buccaneer past. That may be. Nearly as omnipresent here as the threat of nortes is the television set, of which Belize numbers some 12,000. There are also 14 broadcasting outlets which, with comforting historical fitness, pirate satellite signals from the United States and other countries and pass them along as their own. This leads to such further Belizean anomalies as Chicago Cubs fans in San Ignacio and Monkey River -- a cultural presence that may ultimately tip Belizeans toward Uncle Sam (or away) as much as politics or trade.

Cultural anomalies in Belize, however, are nothing new. The country is so rich in archaeological sites, for example, that a Mayan artifact is rarely more than a machete hack away. Graduate students from the United States used to combing a county for a pottery shard, are regularly staggered by the wealth of ornaments and pottery fragments that routinely litter even the few well- worked sites, and by the ancient mysteries at which they hint.

Father Leonard E. Dieckman, a graying Jesuit priest from St. Louis who teaches at St. Johns College in Belize City, has a roomfull of cartons and crates filled with pottery storage jars, obsidian spear blades, pre-classic adz heads, bird-shaped ceremonial whistles, stone corn grinders, beads, necklaces, scrapers, and figurines, many of striking quality and originality, gleaned from a single tiny islet near the city airport. Some of them date from 5,000 B.C.

Star of the collection is the painted figure of a diving god about eight inches long, its body looped backward, feet on head, recovered from the water at the island's edge.

Belizeans who grow up stumbling through such artistic detritus, tend to shrug it off as rubble. Some years ago the minister of public works here in Corozal, to the weeping despair of later visiting archeologists, leveled part of the Santa Rosa Mayan pyramid and used its stones to pave the nearby streets.

Since independence three years ago the government has attempted to stem such practices and awaken national pride in what is increasingly viewed as the country's cultural history. Tomb-looting and the exportation of artifacts are now forbidden by law. A black market in Mayan artifacts continues, however, along with its free- enterprise sibling, a cottage industry in the counterfeit.

The riddle of the Maya's vanished civilization is, of course, not confined to Belize. The more famous sites are those in Guatamala and Yucatan. But there is something in the brooding quality of the landscape here that deepens the enigma and underlines the uneasy sense that in Belize anything can happen.

David Pendergast, an archeologist from the Royal Ontario Museum in Toronto, excavated the ruins of an ancient Mayan handball court in Orange Walk district, for example, and discovered beneath the floor a precisely positioned and still unexplained pot of pure mercury.

While that was a bit confounding it was small beer compared with another archeologist to work in Belize, Denis Puleston of the University of Minnesota. Puleston, excavated several Mayan sites in Belize in the 1970s, and published widely, even experimenting with planting patterns and storage pits to probe the secrets of the Mayans' agricultural economy.

"He was widely respected," said a colleague in Belize City who knew him. "But then he began to get a bit mystical. He found a cave in the mountains in 1978. Caves are sacred to the Mayans, and this one had sone drums in it which have all sorts of taboos associated with them. Puleston staged a drum-beating ritual, which disturbed some of the present day Mayans in the area no end. Then he withdrew into the cave and lived there for several weeks.

"He emerged kind of hollow-eyed, announcing that he had made contact with the ancient Mayas, learned the secret of their civilization and planned to publish it as soon as he could."

Two months later Puleston paid a visit to the sacred Mayan city of Chichen Itza in central Yucatan. He was surprised to find there what appeared to be stone drums like those fashioned from stalagtites in the sacred cave. He tapped on them for a while, then climbed Chichan's highest pyramid: El Castillo, or the Temple of Kukulcan. As he was standing in a tiny room at the top, looking out on a mostly sunny day, he was struck by a tremendous bolt of lightning and instantly killed.

This year, in early January, an archeological survey team ventured into the jungle in the spirit of Pendergast and Puleston seeking the remote Mayan ruins at Lamani and the pyramid temple of the crocodile God. Traveling by four-wheel drive vehicle from road to rut to path, they reached the thatched-hut village of Guinea Grass, a long 10 miles south of Orange Walk, then pushed further inland, past rubber-tired horse- drawn buggies to the Mennonite settlement at Shipyard. There they hired a Spanish-speaking mestizo named Reynaldo who agreed to take them another 15 miles by boat up the New River to Lamani.

After a winding water passage beneath herons and howler monkey nests, through a labyrinth of lianas and mangrove, they reached the lagoon at Lamani with its two square miles of overgrown house mounds and pyramids, from which the jungle stretched green and unbroken for miles, a limitless image from Kipling.

They toured the site in steamy heat. Then one of them asked their guide in halting Spanish if there was anything nearby to drink.

With a gold-toothed grin he led them along a cow path to a nearby village of a dozen thatched-roof huts. There amid a welter of dozing hogs, scratching chickens and open cooking fires, they found a corrugated rooved enclosure with a tiny Honda generator snarling nearby. On the dirt floor inside, beneath pole rafters sagging with old Christmas ornaments of dirty gold paper, stood a rickety counter and an electric refrigerator full of cold beer. And four vacant-eyed Indians mesmerized by a color television set flickering situation comedies in Spanish from Tegucigalpa.