該保(bao)護(hu)區(qu)地(di)(di)理位(wei)置(zhi)為(wei)(wei)(wei):東經126°35′~128°02′,北緯(wei)42°06′~43°51′。總面積(ji)(ji)約114.5萬(wan)(wan)公(gong)頃。其中林地(di)(di)82.3萬(wan)(wan)公(gong)頃,占(zhan)總面積(ji)(ji)71.9%;水(shui)域5.7萬(wan)(wan)公(gong)頃,占(zhan)總面積(ji)(ji)的(de)5.0%。三湖(hu)保(bao)護(hu)區(qu)地(di)(di)處長白山(shan)(shan)(shan)(shan)余脈(mo)(mo)(mo)。四面環(huan)山(shan)(shan)(shan)(shan),西面是(shi)吉林哈(ha)達嶺(ling)(ling)山(shan)(shan)(shan)(shan)脈(mo)(mo)(mo),北面是(shi)老(lao)爺嶺(ling)(ling)山(shan)(shan)(shan)(shan)脈(mo)(mo)(mo),東面是(shi)威虎嶺(ling)(ling)和黃泥嶺(ling)(ling)山(shan)(shan)(shan)(shan)脈(mo)(mo)(mo),南(nan)(nan)面是(shi)老(lao)嶺(ling)(ling)山(shan)(shan)(shan)(shan)脈(mo)(mo)(mo)。地(di)(di)勢東南(nan)(nan)高(gao)西北低。地(di)(di)貌多(duo)為(wei)(wei)(wei)中(高(gao))山(shan)(shan)(shan)(shan)?低(丘)山(shan)(shan)(shan)(shan)?崗(臺)川類。其面積(ji)(ji)比(bi)例大(da)致為(wei)(wei)(wei)七(qi)山(shan)(shan)(shan)(shan)二崗一川。境(jing)內山(shan)(shan)(shan)(shan)巒(luan)起(qi)伏,綿延不斷(duan),溝壑縱橫,異峰突兀。海拔(ba)(ba)800米以上(shang)的(de)山(shan)(shan)(shan)(shan)峰有(you)80余座,其最(zui)高(gao)為(wei)(wei)(wei)南(nan)(nan)樓(lou)山(shan)(shan)(shan)(shan),海拔(ba)(ba)1404.8米,在樺(hua)甸市常(chang)山(shan)(shan)(shan)(shan)境(jing)內;最(zui)低為(wei)(wei)(wei)豐滿壩下,海拔(ba)(ba)約190米。該地(di)(di)區(qu)地(di)(di)質構成多(duo)為(wei)(wei)(wei)玄武巖、石灰巖、土壤(rang)類型為(wei)(wei)(wei)暗棕壤(rang)、白漿(jiang)土、草甸土、棕色森林土、泥炭土等(deng)。
三(san)湖保(bao)護區(qu)處于北(bei)(bei)溫(wen)(wen)(wen)帶大陸性季(ji)風氣(qi)(qi)候區(qu)內。四(si)季(ji)分明,年(nian)、日較差大。春(chun)季(ji)干燥多(duo)風?夏(xia)季(ji)溫(wen)(wen)(wen)熱(re)多(duo)雨?秋季(ji)晴爽?冬季(ji)嚴(yan)寒?年(nian)平均氣(qi)(qi)溫(wen)(wen)(wen)在1.9℃~4.4℃之(zhi)間(jian)?極端高溫(wen)(wen)(wen)36.6℃,極端低溫(wen)(wen)(wen)-45℃。年(nian)≥10℃積溫(wen)(wen)(wen)為(wei)1900℃~2800℃,并呈由(you)(you)南至北(bei)(bei)增加趨(qu)勢?年(nian)日照時(shi)數2350~2450小時(shi)?年(nian)降水量由(you)(you)南向北(bei)(bei)略有減少,為(wei)834~673毫米之(zhi)間(jian)。無霜期大致為(wei)110~130天(tian)。一月(yue)平均氣(qi)(qi)溫(wen)(wen)(wen)約為(wei)-18℃,七月(yue)平均氣(qi)(qi)溫(wen)(wen)(wen)約為(wei)20℃左右。該(gai)區(qu)夏(xia)季(ji)盛行西(xi)(xi)南風,冬季(ji)盛行西(xi)(xi)北(bei)(bei)風。
保護區由于受到三個湖泊(bo)及森林等因素影(ying)響,又具(ju)有湖泊(bo)氣(qi)候、谷地氣(qi)候和(he)森林氣(qi)候的復合(he)特(te)征。